Abstract. A trial was conducted in 30 earthen ponds of approximately 100 m2 to evaluate the effects of nine supplemental feeds containing different protein: energy ratios on the growth and survival of Oreochromis niloticus (L.) in brackish water ponds. The formulated feeds had protein levels of 20%, 25% and 30% each at three energy levels of 3000 kcal, 3500 kcal and 4000 kcal. There was a control (diet 0) with no feeding and mean weight gain, growth rate, feed conversion rate and survival rate were determined. Fingerlings were acclimated from 0 to 29 ppt salinity before the trial and 20% of fish in each treatment were sampled every 30 days to monitor growth changes and adjust the feed. Mean weight gain was significantly different as follows: 30%:4000 kcal (102·21 g); 30% :3000 kcal (93·24g); 25%:3000 kcal (89·79g); 30%:3500 kcal (83·42g); 25%:4000 kcal (78·80g); 25%:3500 kcal (78·13g); 20%:3000 kcal (76·50g); 20%:4000 kcal (71·05g); 20%:3500 kcal (69·68 g) and control (59·11 g). Growth rates were significantly different (P < 0·05) and increased with increasing energy level at the 30% protein feeds but decreased at high energy levels in the 20% and 25% protein feeds. Feed conversion was significantly different due to interaction between protein and energy levels in the feeds, and was better at the 30%:3500 kcal feed, with a feed conversion of 1·55. Survival rates were not significantly different (P > 0·05).