He gained recognition for his distinctive style, which was characterized by immediacy and a deliberate departure from standardized painting techniques.

[citation needed] Fassianos used to design the stage decorations for major classic and modern productions.

His art has been exhibited in museums and galleries including in Athens, Paris, and throughout Europe, as well as in Tokyo, New York, São Paulo, and Melbourne.

[citation needed] Fassianos was very popular in Greece, and some of his works are exhibited in public places: two large murals entitled The Myth of My Neighborhood, can be seen in Athens at the Metaxourgeio metro station.

On 13 December 2007, a Fassianos painting titled The Messenger sold for €550,701 at Bonhams in London.