In this study, Mugil cephalus was exposed to copper, lead and zinc under sub-chronic toxicity test to investigate the effects of growth in terms of gain in length, weight and condition factor of the test organism. The chronic values for copper, lead and zinc was 28, 140, and 93 µg/l respectively. From the data obtained, it is clear that the concentrations of copper, lead and zinc significantly reduced the growth of Juvenile Mugil cephalus when compared with control. Growth effects was observed with the lower concentrations of copper and zinc when compared with lead, at higher concentrations of copper, lead and zinc the relationship with growth was highly significant at P< 0.001. Finally the relationship between concentrations of heavy metals and the growth of the juvenileMugil cephaluswere significant at P<0.05, 0.01 and 0.001.