Reproductive biology of the three dominant species (Sardinella gibbosa, Sardinella fimbriata, and Rastrelliger kanagurta) were studied in Manila Bay from January 2014 to December 2015. The data were collected from landed catch (coming from gillnet, lift net, purse seine, ringnet, and trawl) and during the actual trawl fishing survey. A total of 2,383 Sardinella gibbosa, 2,334 Sardinella fimbriata, and 549 Rastrelliger kanagurta were analyzed by pooling the two years data. The overall female to male ratio conformed to the expected 1:1 sex ratio. These species spawn throughout the year with major peak in March and April and minor peak in October to December for Sardinella gibbosa; with major peak in February to May and minor peak in October to December for Sardinella fimbriata; and for Rastrelliger kanagurta, with major peak in October to December and minor peak in May and June. The GSI values correlate with the maturation of the gonads of these species. The length at maturity (Lm50) was calculated at 12.75 cm in males and 13.25 cm in females for S. gibbosa; 12.25 cm in males and 12.75 cm in females for S. fimbriata; and 25.5 cm in males and 24.5 cm in females for R. kanagurta.