Methyl jasmonate at a concentration of 0.5% in lanolin paste was applied to detached mature green tomatoes cv. Venture. It caused the formation of a yellow colored epidermis and parenchyma at a depth of 2 mm on the place of treatment. Untreated areas, and areas treated with lanolin paste alone, developed a normal red color at the fully ripened stage. Analyses of carotenoid compositions showed that methyl jasmonate almost totally inhibited lycopene accumulation and stimulated -carotene accumulation in the ripening of tomatoes.