Assadour spent his early years in Beirut, studying under various artists including the renowned Lebanese Armenian painter, Paul Guiragossian. Time spent working with Jean Khalife at the Italian Cultural Institute led to the artist being granted a scholarship to study in Italy in 1961. Assadour went on to settle in Paris in 1964, attending the École Supérieure des Beaux-Arts where he studied engraving under Lucien Coutaud, it was here that he developed his distinctive, detailed style of etching.