The objective of the study was to assess the variability in the age at puberty of growing pigs on melatonin and vitamin E supplementation during summer and winter seasons. 36 nos. of weaned crossbred (Hampshire X Assam local) female pigs were selected for the study. Eighteen (18) animals were subjected to treatment during summer and 18 animals were subjected to treatment during winter. The selected animals were divided into three groups, with six pigs in each group, consisting of the control group (Treatment 1), a second group comprising of animals fed with melatonin (Meloset) @3 mg/animal (Treatment 2) and a third group in which the animals were fed Vitamin E (Evion) @100 mg (Treatment 3), for both summer and winter season separately. To determine the age at puberty, individual animals were exposed to boar and the behavioral and physical signs were observed. Statistical analysis revealed significant difference (P<0.01) in the mean age at puberty between treatment and between season with the THI being 82±0.50 during summer and 63±0.30 during winter season.