High amount of turbidity was identified as one of the important factor affecting the successful cultivation of microalgae in palm oil mill effluent (POME). In this study, Chlorella sorokiniana was cultivated in POME, under different dilutions of 80, 60, 40 and 20% (v/v) with distilled water. The aim of the study is to investigate the effect of POME turbidity and the dilutions on the specific growth rate of microalgae. The results found that, C. sorokiniana grew on both sterilized and unsterilized condition. The result of the batch experiment showed that, POME turbidity of 45 NTU produce the maximum specific growth rate by C. sorokiniana of 0.14 d-1, which correspond to biomass production of 4.06 g/L and 0.2 d-1, which correspond to biomass production of 5.94 g/L in sterilized and unsterilized POME respectively. The POME of high turbidity concentration of 98 NTU yield only 0.07 d-1 maximum specific growth rate of algae. Results of this study identified 80% dilution as the optimal medium that can enhance maximum biomass production in POME. This could be useful in reducing the cost of bioenergy generation