In 1840 he obtained a study grant which enabled him to spend four years in Rome studying painting. He was inspired by the masters of the Quattrocento and in 1844 he opened a school in Florence, where among his students were Silvestro Lega and Michele Gordigiani.
Mussini's wife Luigia Mussini Piaggio, also a painter, died in labor in 1865 giving birth to their daughter Luisa Mussini who became the wife (and assistant) in 1893 of her father's former pupil Alessandro Franchi.