This study describes the bioconversion efficiency and yield of Pleurotus ostreatus (Jacq. ex Fr.) Kummar cultivated on cassava and sugarcane peels substrates. Two percent lime and wheat bran were added to stabilize the pH and enrich the substrate with nitrogen. The treatments for this investigation comprised T1 (100% cassava peels - control), T2 (75% cassava peels + 25% sugar cane peel), T3 (50% cassava peels + 50% sugar cane peel), T4 (25% cassava peels + 75 sugar cane peel), and T5 (0% cassava peel + 100% sugar cane peel). The experiment was laid out in a completely randomized design (CRD) and replicated three times in a specially constructed growth chamber. Yield parameters evaluated include mean mushroom weight in grams, mean number of mushrooms, stipe length (cm), pileus diameter (cm), dry weight of fruit bodies (g), dry matter loss (%), biological efficiency (%), bioconversion efficiency (%), and number of mushroom flushes. The nutritional composition of the fruit bodies was determined.  The result obtained from the evaluation of the yield  attributes  revealed significant differences in the following yield parameters namely mean mushroom weight  (2.63–32.8 g), mean number of mushroom (1–11.5), pileus diameter (2.56–15.95 cm), length of stipe (1.53–5.85 cm), dry matter loss (23.30–157.5%), dry weight of fruit bodies (0.76–6.67 g), stipe girth (1.3-8.0 cm), biological efficiency (0.26–3.28%), bioconversion efficiency (0.11–0.68%), mean number of mushroom flushes (0.67–2.0) and yield duration (25.67–41.0 days).The result further revealed significant differences in the nutritional compositions of the mushroom fruit bodies: moisture content (20.30–25.07%), crude fiber (1.05–1.27%),ash (0.89–1.01%),  protein (30.7–44.38%),crude fat (1.62–1.83%), total soluble carbohydrate (TSC) (28.87–44.18%). The 15.8%, 31.5%, 47.4% and 5.3% of the total mushroom fruit bodies harvested belonged to the ‘very small’, ‘small’, ‘medium’ and ‘very big’ categories, respectively. T5 was the outstanding in supporting the colonization, yield and bioconversion efficiency of P. ostreatus. This study concludes that P. ostreatus should not be cultivated on cassava peels alone. Supplementing the sugarcane peels with cassava peels increases the protein content of the fruit bodies.