The growth, survival and profitability of milkfish (C. chanos ) and prawn (Penaeus monodon ) (averaging 3.1 g and 0.3 g, respectively) grown in five different combinations for 100 days in 500-m super(2) brackishwater ponds in the SEAFDEC Station at Leganes, Iloilo, Philippines were assessed. The treatments with three replicates each were (I) 2,000 milkfish/ha; (II) 4,000 milkfish/ha; (III) 6,000 prawns/ha; (IV) 2,000 milkfish with 6,000 prawns/ha; and (V) 4,000 milkfish with 6,000 prawns/ha. the competition of prawns to milkfish as expressed by the competition index (CI) was 0.03 and 0.15 compared to the competition exerted by milkfish to prawn (0.48 and 0.67). Mean weight gain of milkfish at 2,000/ha was significantly higher (L = 0.05) than those at 4,000/ha in both monoculture and polycuture systems. the monoculture of prawn (III) was significantly higher (L = 0.05) than that of prawns in polyculture with milkfish (IV and V). Likewise, prawns stocked with milkfish at a lower stocking density (IV) grew signficicantly faster than those at higher stocking density (V).