The present investigation were carried out understand heterosis and gene action for yield and quality traits in cucumber genotypes. The materials consist of three lines and four testers and the resultant 12 hybrids through Line x Tester mating design. The present estimation of heterosis identified that L2XT2 (Koradacherry local x Orathanadu local) being the superior hybrid for most of the traits by expressing higher significance Relative Heterosis, Heterobeltiosis and Standard Heterosis. The gene action reveals that the ratio for all the traits expressed less than 1 indicates the nonadditive gene action. The proportional contribution was higher in Lines x Testers interaction than lines and testers. | Heterosis and gene action for yield and quality traits in cucumber (Cucumis sativus L.)