The experiment was conducted at the Department of Horticulture, C.S.A. University of Agriculture and Technology, Kanpur during the year 2014-15 to find out effect of seedling age on growth and flowering attributes 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 (44 days) and three replications. Observations were recorded on growth and flowering attributes i.e., height of plant, spread of plant, number of primary branches/plant, number of secondary branches/plant, day to first flower initiation and number of flower per plant. The results showed that T3 (24 days old seedling) increased significantly to plant height, spread of plant (N-S,E-W), and number of flowers/plant revealing 63.19 cm maximum plant height, maximum plant spread 116.18 cm (N-S) and 171.13 cm (E-S), and maximum number of flower/plant (69.64) respectively. Treatment T4 (28 days old seedling) enhanced number of primary branches (7.35) which was greater variation among treatments while number of secondary branches were significantly influenced (9.65) with T4 treatment also. Days to first flower initiation was significantly enhanced with T1 treatment (62.15 days).