Matuszyński's father, Jan Fryderyk Matuszyński (1768–1831), was a physician and surgeon and head of the Lutheran Hospital in Warsaw.
Jan Matuszyński, who was born in Warsaw, became a friend of Chopin whilst attending the Warsaw Lyceum, where he was taught by Chopin's father, Nicolas Chopin. Matuszyński came from a musical family; he himself played the flute, and his brother Leopold (1820–93) became an operatic tenor and director.
Leaving for exile in Germany following the suppression of the uprising, he eventually graduated in medicine at the University of Tübingen.
Emigrating to Paris in 1834, he for a time shared Chopin's apartment in the Chaussée d'Antin and gave him medical advice.
He took a further medical degree in Paris, specializing in physiology, and married a Frenchwoman, Caroline Boquet.
In 1837 he published a treatise, "De l'influence du nerf sympathique sur les fonctions des sens (On the Influence of the Sympathetic Nervous System on the Functions of the Senses)."
He died of tuberculosis. in his last days, Chopin and George Sand had him cared for at the rooms they shared in the Rue Pigalle. Sand wrote that he "died in our arms after a slow and cruel agony, which caused Chopin as much suffering as if it had been his own. He [Chopin] was strong, courageous and devoted... but when it was over he was shattered."