The numbers and categories used below are from the Kinsky catalog of 1955. WoO is an abbreviation of "Werke ohne Opuszahl", German for "Works without Opus number".
Instrumental works: WoO 1–86
Orchestral works
Orchestra alone
Concertante
Dances
Marches and dances for winds
Chamber works
Without piano
With piano
Piano works for 2 or 4 hands
Sonatas and single-movement works
Variations
Dances
Vocal works: WoO 87–205
Cantatas, choruses and arias with orchestra
Works for multiple voices with piano accompaniment, or unaccompanied
Lieder and songs for solo voice and piano
Folksong arrangements for one or more voices, with piano trio accompaniment
Vocal canons
Musical jokes, quips, and dedications
WoO 1: Musik zu einem Ritterballett (Music for a ballet on horseback) – eight movements
WoO 2a: Triumphal March for orchestra for Christoph Kuffner's tragedy Tarpeja (1813)
WoO 2b: Prelude to Act II of Tarpeja (1813)
WoO 3: "Gratulations-Menuett", minuet for orchestra
WoO 4: 降E大调钢琴协奏曲(第0号钢琴协奏曲) Piano Concerto in E-flat major (solo part only with indications of orchestration), occasionally referred to as Beethoven's Piano Concerto No. 0
WoO 5: Violin Concerto movement in C major, fragment
WoO 6: Rondo in B-flat major for piano and orchestra, fragment, possibly part of initial version of the Piano Concerto No. 2
WoO 7: 12首小步舞曲 Twelve minuets for orchestra
WoO 8: Twelve German Dances for orchestra (later arranged for piano)
WoO 9: Six minuets for two violins and cello
WoO 10: 6首小步舞曲 Six minuets for orchestra (original version lost, only an arrangement for piano is extant)
WoO 11: 7首兰德勒舞曲 Seven Ländler for two violins and cello (original version lost, only an arrangement for piano is extant)
WoO 12: Twelve minuets for orchestra (probably spurious, actually by Beethoven's brother Carl)
WoO 13: Twelve German Dances for orchestra (only a version for piano is extant)
WoO 14: Twelve contredanses for orchestra
WoO 15: Six Ländler for two violins and cello (also arranged for piano)
WoO 16: Twelve Écossaises for orchestra (probably spurious)
WoO 17: Eleven "Mödlinger Tänze" for seven instruments (probably spurious)
WoO 18: March for Military Band "For the Bohemian Ward" (trio added later)
WoO 19: March for Military Band (trio added later)
WoO 20: March for Military Band "Zapfenstreich" (trio added later)
WoO 21: Polonaise for Military Band
WoO 22: Écossaise for Military Band
WoO 23: Écossaise for Military Band (only a piano arrangement by Carl Czerny is extant)
WoO 24: March for Military Band
WoO 25: Rondo for 2 oboes, 2 clarinets, 2 horns and 2 bassoons (original finale of the Octet, opus 103) (1792)
WoO 26: 长笛二重奏 Duo for two flutes
WoO 27: 3首木管二重奏 Three duets for clarinet and bassoon (possibly spurious)
WoO 28: 根据莫扎特歌剧《唐璜》中《请伸出你纤巧的双手》主题的12段变奏曲Variations for two oboes and cor anglais on "Là ci darem la mano" from Mozart's opera Don Giovanni
WoO 29: March for Wind Sextet in E-flat (2 clarinets, 2 horns & 2 bassoons)
WoO 30: Three Equale for four trombones – Vocal arrangements of these were performed at Beethoven's funeral.
WoO 31: Fugue for organ
WoO 32: 弦乐二重奏 Duo for viola and cello, "mit zwei obligaten Augengläsern" ("with two obbligato eyeglasses")
WoO 33: Five pieces for mechanical clock or flute
WoO 34: Duet for two violins
WoO 35: Canon for two violins
WoO 36: Three piano quartets
WoO 37: 三重奏 Trio for flute, bassoon, and piano in G major (1786)
WoO 38: 第9号钢琴三重奏 Piano Trio No. 9 in E-flat major
WoO 39: 第八钢琴三重奏 Allegretto for piano trio in B-flat major (Piano Trio No. 8)
WoO 40: 根据莫扎特歌剧《费加罗的婚礼》中《伯爵若要跳舞》主题而作的12段变奏曲 Twelve variations for piano and violin on "Se vuol ballare" from Mozart's The Marriage of Figaro (1792-93)
WoO 41: Rondo for piano and violin in G major (1793-94)
WoO 42: Six German Dances for violin and piano (1796)
WoO 43a: Sonatina for mandolin and harpsichord
WoO 43b: Adagio for mandolin and harpsichord
WoO 44a: Sonatina for mandolin and piano
WoO 44b: Andante and variations for mandolin and harpsichord
WoO 45: 为大提琴和钢琴而作的变奏曲 Twelve Variations for cello & piano in G major on Handel's "See, the Conqu'ring Hero comes,"
WoO 46: 根据莫扎特歌剧《魔笛》中《知道爱情的男人》主题而作的7段变奏曲Seven Variations for cello & piano in E-flat major on Mozart's "Bei Männern,"
WoO 47: 3首为选帝侯而作的钢琴奏鸣曲 Three piano sonatas (E-flat major, F minor, D major) ("Kurfürsten Sonatas") (1783)
WoO 48: Rondo for piano in C major (1783)
WoO 49: Rondo for piano in A major (1783)
WoO 50: Piano Sonata in F major (1790–92)
WoO 51: Piano Sonata in C major (1797–98, fragment)
WoO 52: Presto (Bagatelle) for piano in C minor (1795, rev. 1798 and 1822)
WoO 53: Allegretto (Bagatelle) for piano in C minor (1796–97)
WoO 54: 钢琴小品“快乐与悲伤” Lustig-Traurig (Bagatelle) for piano in C major (1802)
WoO 55: Prelude for piano in F minor (1803)
WoO 56: Allegretto (Bagatelle) for piano in C major (1803, rev. 1822))
WoO 57: 可爱的行板 Andante Favori – original middle movement from Piano Sonata No. 21 (Waldstein) (1805)
WoO 58: Cadenzas for 1st and 3rd movements of Mozart's D minor Piano Concerto (K. 466)
WoO 59: 钢琴小品“致爱丽丝” Poco moto (Bagatelle) for piano in A minor, "Für Elise" (c. 1810))
WoO 60: Ziemlich lebhaft (Bagatelle) for piano in B-flat major (1818))
WoO 61: Allegretto for piano in B minor (1821)
WoO 61a: Allegretto quasi andante for piano in G minor (1825)
WoO 62: String Quintet in C major (Fragment, Piano Transcription)
WoO 63: 德莱斯勒进行曲主题变奏曲 Nine variations for piano on a march by Ernst Christoph Dressler (1782)
WoO 64: 瑞士歌曲主题小变奏曲 Six Variations on a Swiss song for piano or harp (1790-1792)
WoO 65: 李基尼抒情小调主题变奏曲 Twenty-four variations for piano on Vincenzio Righini's aria "Venni Amore" (1790-1791)
WoO 66: 迪塔斯多夫抒情小调主题变奏曲 Thirteen variations for piano on the aria "Es war einmal ein alter Mann" from Carl Ditters von Dittersdorf's opera Das rote Käppchen
WoO 67: Eight variations for piano four hands on a theme by Count Waldstein
WoO 68: 海贝尔小步舞曲主题变奏曲 Twelve variations for piano on the "Menuet a la Vigano" from Jakob Haibel's ballet La nozza disturbate (1795)
WoO 69: 拜谢罗咏叹调主题变奏曲 Nine variations for piano on "Quant'e piu bello" from Giovanni Paisiello's opera La Molinara
WoO 70: 拜谢罗二重唱主题变奏曲 Six variations for piano on "Nel cor piu non mi sento" from Giovanni Paisiello's opera La Molinara (1795)
WoO 71: 伍拉尼茨基舞曲主题变奏曲 Twelve variations for piano on the Russian dance from Paul Wranitzky's ballet Das Waldmädchen
WoO 72: 格莱特里浪漫曲主题变奏曲 Eight variations for piano on "Une Fièvre Brûlante" from André Ernest Modeste Grétry's opera Richard Coeur-de-lion
WoO 73: 萨列里二重唱主题变奏曲 Ten variations for piano on "La stessa, la stessissima" from Antonio Salieri's opera Falstaff
WoO 74: "Ich denke dein" — song with six variations for piano four hands
WoO 75: 维特四重唱主题变奏曲 Seven variations for piano on "Kind, willst du ruhig schlafen" from Peter Winter's opera Das unterbrochene Opferfest
WoO 76: 苏斯迈耶尔三重唱主题变奏曲 Eight variations for piano on "Tandeln und scherzen" from Franz Xaver Süssmayr's opera Soliman II
WoO 77: G大调主题变奏曲 Six easy variations on an original theme for piano
WoO 78: C大调英国国歌变奏曲 Seven variations for piano on "God Save the King"
WoO 79: “保卫大不列颠”主题变奏曲 Five variations for piano on "Rule Britannia"
WoO 80: c小调32段变奏曲 Thirty-two variations on an original theme in C minor for piano
WoO 81: Allemande for piano in A major
WoO 82: Minuet for piano in E-flat major
WoO 83: Six Écossaises for piano and orchestra in E-flat major
WoO 84: 圆舞曲 Waltz for piano in E-flat major
WoO 85: 圆舞曲 Waltz for piano in D major
WoO 86: 降E大调埃科塞斯舞曲 Écossaise for piano in E-flat major
WoO 87: Cantata on the Death of Emperor Joseph II
WoO 88: Cantata on the Accession of Emperor Leopold II
WoO 89: Aria "Prüfung des Küssens"
WoO 90: Aria "Mit Mädeln sich vertragen"
WoO 91: Two arias for Die Schöne Schusterin (1795)
WoO 92: Aria "Primo Amore"
WoO 92a: Aria "No, non turbati"
WoO 93: Duet "Nei giorni tuoi felice"
WoO 94: "Germania," aria with chorus in B-flat major (1814)
WoO 95: Chorus for the Congress of Vienna
WoO 96: Incidental Music to Leonore Prohaska (1815)
WoO 97: "Es ist vollbracht" for Die Ehrenpforten (1815)
WoO 98: "Wo sich die Pulse," chorus for The Consecration of the House
WoO 99: Italian Partsongs
WoO 100: Musical joke for three voices "Lob auf den Dicken"
WoO 101: Musical joke for three voices and chorus "Graf, Graf, liebster Graf"
WoO 102: Chorus for male voices "Abschiedsgesang"
WoO 103: Cantata Un lieto Brindisi
WoO 104: "Gesang der Mönche" from Schiller's Wilhelm Tell for three male voices
WoO 105: Song for solo voice, chorus and piano "Hochzeitslied"
WoO 106: Birthday Cantata for Prince Lobkowitz
WoO 107–130: Twenty-four songs
WoO 131: Unfinshed song "Erlkönig"
WoO 132: Song "Als die Geliebte sich trennen wollte"
WoO 133: Song "In questa tomba oscura"
WoO 134: Song "Sehnsucht" in four settings
WoO 135–151: Seventeen Songs
WoO 152: 25首爱尔兰民歌 Twenty-five Irish folksongs
WoO 153: 20首爱尔兰民歌 Twenty Irish folksongs
WoO 154: 12首爱尔兰民歌 Twelve Irish folksongs
WoO 155: Twenty-six Welsh folksongs
WoO 156: Twelve Scottish folksongs
WoO 157: 12首各国民歌 Twelve folksongs of various nationalities