Six fungal isolates belong to Aspergillus niger, Penicillium spp., and Pleurotus osstreatus were used for decolourization activities of some acid and reactive dyes, after they screened for optimum efficiency and the condition for temperature and pH were optimized The results obtained indicated that Pleurotus osstreatus and Aspergillus niger 1 and 2 are more efficient than Penicillium spp., with the two kinds of dyes used.