He developed a highly individual Romantic style of painting, in which richly colored, dappled, textured and glazed surfaces produce a scintillating effect. He painted courtly subjects inspired by Antoine Watteau; he also painted still lifes, portraits, and Orientalist subjects that owe much to the example of Delacroix.
Confronted with criticism of his style of painting Monticelli himself remarked, "I paint for thirty years from now". His work reached its greatest spontaneity in the decade before his death in 1886.