Lefteris Economou studied art in London, at St Martins School of Art (1949-1950), the John Cass School of Art (1950-1954) and Goldsmiths College of the University of London (1954-1955). In 1955 he was appointed as an art teacher in the high schools of Cyprus, a post he maintained until his retirement.

Economou first appeared on the art scene in 1952 when he took part in a group exhibition in London, and he remained consistently active in the art world thereafter. He was interested in all subjects, including landscape, portraiture, genre painting and still-life compositions, and his work reveals the strong influence of Impressionism and Post-Impressionism. In some of his most important pieces, he synthesized free-form and precise shapes in a distinctive manner, fusing different styles of drawing. He wrote and illustrated books, which he published himself; he favoured large surfaces in his printmaking and also painted many large murals. His engravings are notable for their sharply drawn features and overall high quality.