In 1828 he enrolled at the Brera Academy and around this period he joined the Mazzinian activism but after a failed conspiracy he was sentenced to death, only to be pardoned but exiled.

Vassalli assisted in excavations at Giza and Saqqara until 1860, when he gave resignation and returned again home to give his contribution to the Expedition of the Thousand led by Giuseppe Garibaldi.

He sent many mummy remains to the Museo Civico di Storia Naturale of Milan and in 1871 he made around 150 casts from monuments exhibited in the Bulaq Museum which he brought to Florence with him.

During his short stay here the Italian government asked him to inspect many Egyptian collections in Italy, after which he returned to his duties in Cairo.

This fact sparked a controversy over a century later, when in a 2015 research the Egyptologist Francesco Tiradritti suggested that the Meidum geese scene is a 19th-century forgery possibly made by Vassalli himself, a claim dismissed by Egyptian authorities.