A study was conducted to determine the gonadosomatic index (GSI) and fecundity of Labeo rohita during the period of March 2013 to February 2014. From this study it has been shown that fecundity of fish increases with increase in size, weight of fish and gonad weight. The fecundity of Labeo rohita varied from 19,950 eggs in fish of 155mm length (TL) to 2,01,150 in fish of 300 mm length (TL).The gonads attain the maximum weight 5.75± 0.78 and 11.5±1.45 for males and females respectively in July and minimum (0.55± 0.25 male and 1.05 ±0.18 female) in November. The fish has only one spawning season of short duration running from June to August as indicated by the peaks of gonadosomatic index and Ova diameter.