Bahman Mohassess was born in Rasht, Iran in 1931. At age fourteen he started attending the shop of Mohammed Habib Mohammadi, a painter who had studied at the Moscow Art Academy.

In 1950 Bahman Mohassess enrolled in the Tehran Fine Art Academy but never attended. In 1954 he moved to Italy to pursue his art studies. He attended the Rome Arts Academy, and for a few months attended the art studio of Ferruccio Ferrazzi. He participated in various collective shows in Italy and abroad such as the Bienniale of Venice; and exhibitions in Sao Paulo, Brazil; and Paris, France. He also had a series of one-man shows. His works in style ranged from Abstract Expressionism early on and then to Expressive Figurative.  He also did sculpture.

In 1964, Mohassess returned to his home country, Iran, hoping to create a stimulating and creative art environment in Iran, one following the European Art movements and scene. He spent four years in Teheran between 1964 and 1968, before finally returning to Rome. Perhaps the best creative era of Bahman Mohassess was between 1964-1968, while he was residing in Iran. Mohassess left Iran in 1969 only to return periodically to Iran. After the Iranian revolution of 1979 a majority of his work was destroyed by the Islamic Republic or was destroyed by himself.

Bahaman Mohassess died in Rome, Italy on July 28, 2010.