- Hess 33. Minuet in A-flat, String Quartet. Composed ca. 1790. (Exists also in pianoforte version).
- op. 3. String Trio in E-flat. Composed before 1794. Published Vienna, 1796. (Fragment arrangement by Beethoven for pianoforte trio).
- op. 4. String Quintet in E-flat. Composed in 1795. Published Vienna, 1796. (Thorough compositional revision of the Octet, op. 103 (see 'Chamber Music for Wind alonge and with Strings').
- op. 87. Transcription of Trio for 2 oboes and English horn op. 87 as string trio in C. Composed in 1794. Published Vienna, 1806. (Transcription probably approved by Beethoven).
- WoO 32. Duet in E-flat, for viola and violoncello, 'Mit zwei obligaten Augenglaesern', first movement and minuet. Composed in 1796-1797. Probably written for Nikolaus Zmeskall von Domanovecz. First movement published Leipzig, 1912, minuet Frankfurt am Main, London and New York, 1952.
- op. 8. Serenade in D, String Trio. Composed in 1797-1798. Published Vienna, 1797
- op. 9. Three String Trios in G, D, and c. Composed in 1797-1798. Dedicated to Count Johann Georg von Browne. Published Vienna, 1798
- Hess 28. Another trio for the minuet of op. 9 no. 1 in G. Composed in 1797-1798. Published Bonn, 1924.
- op. 29. String Quintet in C. Composed in 1801. Dedicated to Count Fries. Published Leipzig, 1802.
- Hess 34. Arrangement of Pianoforte Sonata op. 14 no. 1 for string quartet in F. Written in 1801-1802. Dedicated to Baroness Josefine von Braun. Published Vienna, 1802.
- op. 104. Arrangement of Pianoforte Trio op. 1 no. 3 for String Quintet. Written in 1817. Published Vienna and London, 1819. (Arrangement corrected by Beethoven, but largely the work of someone else).
- Hess 40. Prelude in d, String Quintet. Probably composed in 1817. Published in Smz, Nov. (1905).
- op. 137. Fugue in D, String Quintet. Composed in 1817. Published Vienna, 1827.
- WoO 34. Duet in A, for 2 violins. Composed in 1822. Dedicated to Alexandre Boucher. Published in: T. von Frimmel, 'Ludwig van Beethoven' (Berlin, 1901).
- Hess 41. String Quintet in C, fragment. Composed in 1826. Published Vienna, 1838. (Survives only in pianoforte transcription, WoO 62).