The breeding biology of Malabar sole Cynoglossus macrostomus Norman, a small flatfish that supports a commercial fishery in Kerala was studied during 1994-95 and 1995-96 for maturity, spawning fecundity and sex ratio. Both sexes attain maturity at 97 mm in total length. There are two broods in an year from the spawnings, one during the post monsoon and the other from the second spawning during the premonsoon period. Ova diameter studies showed that the individual fish spawns only once in an year. The fecundity increased with increase in length. The lowest and highest fecundity was 5021 and 64434 in 76 mm and 156 mm size groups respectively. During most of the months males dominated. Mathematical equations describing the fecundity relationships with length and weight of the fish and ovary have been worked out.