Effect of dietary tricalcium phosphate (TCP) on the availability of zinc (Zn) and manganese (Mn) in juvenile redlip mullet were investigated. Fish were fed eight purified diets for 12 weeks in a flowthrough system at 20.5-22.0°C. A 6.45% TCP supplementation to the diet containing 30 mg Zn and 20 mg Mn/kg, did not affect the weight gain of fish, however, decreased the Zn content of vertebrae compared to fish fed the control diet with 30 mg Zn and 20 mg Mn/kg and 0.3% Ca from Ca-lactate. Higher levels of Zn supplementation (60 mg Zn/kg, 120 mg Zn/kg) to the TCP supplemented diets improved the Zn status but decreased the Mn content of vertebrae and whole body. On the other hand, higher levels of Mn supplementation (40 mg and 80 mg/kg) to the TCP supplemented diets increased the Mn content, however, decreased the Zn content in whole body and vertebrae. When higher levels of Zn and Mn were added simultaneously to the TCP supplemented diet, both Zn and Mn contents of whole body and vertebrae were in normal levels. It appears that a balance in dietary Zn and Mn supplements is necessary for juvenile redlip mullet.