Abstract: Studies were carried out on the degradation of cotton waste, rice straw and cocoa pod husks using Pleurotus pulmonarius in cultures incubated for 0-60 days. The proximate composition, percentages of nitrogen, carbon, potassium and phosphorus, pH, lignin contents, organic matter and enzyme production were determined using the substrates degraded by P. pulmonarius. Crude protein increased significantly throughout the incubation period from 1.27% in the control to 12.63% in cotton waste, 6.65% to 14.82% in rice straw and in cocoa pod husk from 7.04% to 13.82%. Crude fibre decreased significantly in cotton waste and cocoa husk from 5.88% to 5.31% and from 39.88% to 34.95% respectively but an increase was observed in rice straw from 18.42% in control to 28.08% after 60days of incubation period. The nutrient contents, pH values, organic matter showed significant differences of (P≤0.05) in the three substrates as the days of fermentation increased. Lignin contents of treated cotton waste and cocoa husk were degraded by Pleurotus pulmonarius but an increase was observed in the rice straw. Cellulase activities decreased significantly in contrast to the lignase activities where a consistent increase was observed on the degraded substrates as the incubation period increased
