Abstract: The antibacterial effect of crude polysaccharide extracts of the sclerotial mushroom Pleurotus tuber-regium on some bacterial pathogens were investigated using the agar cup diffusion and disc diffusion methods. Ethanolic polysaccharide extracts of P tuber-regium fruitbody showed mean inhibition zones of 19.33, 20.67, 23.00 and 26.67 mm on Enterococcus feacalis, Escherichia coli, Staphylococcus aureus and Salmonella typhi respectively. The ethanolic extracts of the sclerotium and aqueous extracts of both the sclerotium and fruitbody did not produce any observable zones of inhibition. None of the extracts showed visible zones of inhibition in the disc diffusion technique. The Minimum Inhibitory Concentrations (MIC) determined by the agar cup diffusion techniques for the ethanolic extracts from the fruit body were 6.25 mg mL 1, 12.5 mg mL 1 and 12.5 mg mL 1and 25 mg mL 1 for Staphylococcus aureus Escherichia coli Salmonella typhi and Enterococcusfeacalis respectively.