Aspects of the reproductive biology of which included the sex ratio, gonado-somatic index, stages of gonadal development and fecundity of the grunt, Pomadasys jubelini in the New Calabar-bonny River were investigated. Pomadasys jubelini had a sex ratio of 1: 2.1 (male to female). Gonado-Somatic Index ranged from 1.33 to 4.41% (2.89±0.03%). High gonado-somatic indices were recorded from September to October. Two stages of gonad maturation, maturing and mature were observed for male fish while the stages of quiescent, maturing and mature were observed for female fish. Fecundity ranged from 9,085 to 37,926 eggs (25,852±176 eggs). Correlation of fecundity- body weight (r=0.15) and fecundity body-length showed that fecundity was more related to weight than length. Pomadasys jubelini spawned during the rainy season between August and October during which large number of fingerlings and juveniles were obtained fresh water and estuarine environments.