Abstract: The growth of the aquaculture industry in Nigeria depends to some extent on the availability of fish seeds. This study was carried out to measure the optimum growth of Heterobranchus bidorsalis and the best time to crop under maximum utilization of feed in semi-intensive pond condition. Optimum growth performances of 330 fingerlings of artificially propagated Heterobranchus bidorsalis were investigated. The fingerlings were stocked in three 0.02 hectares earthen ponds on the 1st of February, 2010. Mean weight at stocking was 8.5±1.5 g. The fish were fed 3% of their body weight two times daily with compounded artificial feed containing 45% crude protein. Temperature, dissolved oxygen, pH and total ammonia-nitrogen were measured in each treatment. Survival rate, specific growth rate and condition factor of fish species were also determined. Survival at harvest (after 26 weeks) was 75.5% and the mean weight of the fish was 850±73.06 g. Standing crop at harvest was 10,580 kg ha-1. There was positive correlation (0.99) between growth of Heterobranchus bidorsalis and the number of weeks of growth study of the fish. Mean condition factor (K) was 1.24. Result demonstrated the potential of Heterobranchus bidorsalis for use in aquaculture. It also indicates that the fish species can be grown to commercial size within 26 weeks from fingerling stage under semi-intensive pond conditions. The best time to harvest the fish for maximum gain in terms of good growth and maximum profit on feed utilization is 26 weeks after hatching.