The experiment was conducted at the Department of Horticulture, C. S. A. Univ. of Agri. & Tech., Kanpur during the year 2014-15 to find out “Influence of seedling age on yield attributes and yield of tomato (Lycopersicon esculentum Mill.)”.Randomized block design(RBD) was used with eight treatments of seedling age i.e.T1 (16 days), T2 (20 days), T3 (24 days), T4 (28 days), T5 (32 days), T6 (36 days), T7 (40 days) and T8 (40 days) and three replications. Observations were recorded on yield attributes and yield i.e. number of fruit/plant, diameter of fruit, weight of fruit, days required for fruit ripening after transplanting, fruit weight/plant (g) and yield (q)/ha. The results showed that treatment T3 (24 days old transplant) increased significantly to number of fruit/plant, weight of fruit and fruit yield/ha revealing 31.72 fruits,41.55g per fruit and 308.63 q/ha. Whereas, T3 treatment revealed maximum 725 g yield/plant which is superior than all the treatments. Maximum 4.41 cm diameter obtained by T4 (28 days old transplant) significantly higher to all treatments. T1 (16 days old transplant) required maximum 71.65 days for fruit ripening which was significantly superior to all the treatments. The minimum 52.84 days required for fruit ripening by T8 (44 days old transplant) treatment.