Guayasamín was born in Quito, Ecuador. 
Guayasamín won the first prize at the Ecuadorian Salón Nacional de Acuarelistas y Dibujantes in 1948. He also won the first prize at the Third Hispano-American Biennial of Art in Barcelona, Spain, in 1955. In 1957, at the Fourth Biennial of São Paulo, he was named the best South American painter.