He moved to continue his education with Jean-Henri Levasseur and Louis-Pierre Norblin at the Conservatoire de Paris, where he won his first prize only after one year.

Franchomme forged close friendships with Felix Mendelssohn, when the latter visited Paris in 1831, and with Franz Liszt as well as Frédéric Chopin.

In 1833, Chopin and Franchomme collaborated to write a Grand Duo concertant for piano and cello, based on themes from Giacomo Meyerbeer's opera Robert le diable.

Franchomme was among the most celebrated cellists of his time and contributed to the refinement of the bowing technique—elegant, sweet, and light—which distinguished the French school developed by Jean-Pierre and Jean-Louis Duport.

On 3 May 1856, the Weekly Chronicle and Register noted that he "carefully abstains from all abuse of the tremolo and of the exaggerated expression which are the distinguishing features in most modern violoncello playing".