The effect of the COVID-19 on meat supply chain has increased the need for alternative sources of high-quality, protein-rich foods to combat rising food insecurity and malnutrition. First cultivated for food in Germany during World War I, Pleurotus ostreatus (Oyster mushroom) is reported for its numerous nutritional and health-benefits. This study compared the nutrient and anti-nutrient composition of mushrooms grown on different substrates. A mixture of the substrates (rice bran + saw dust (Ms/r) (1:2) or ground banana leaves (Mb)) with water containing CaCO3 were first sterilized for 15 minutes at 121oC and 15 psi in heat-resistant, transparent polythene bags before aseptically inoculating with the stock culture (spawn). The bags were then transferred into the growth room (relative humidity 75-85%) 20 days post-inoculation after total colonization with fungi hyphae. Ms/r had significantly higher yield (1250g) as well as carbohydrate (14.16%), Na (79.35mg/100g), and Cl (121.86mg/100g) contents compared to Mb (250g, CHO (8.01%), Na (70.15mg/100g), and Cl (108.28mg/100g) respectively). On the other hand, protein (8.43%), K (574.48 mg/100g), vit B1 (0.1480mg/100g), and vit D (134.83IU) contents of Mb were significantly higher when compared to Ms/r (protein (2.75%), vit B1 (0.0750 mg/100g), and vit D (104.07IU)). The anti-nutrient analysis of the mushrooms revealed higher oxalate (78.93 mg/100g) and significantly lower phytate (42.41 mg/100g) contents in Ms/r when compared to oxalate (42.5) and phytate (59.88 mg/100g) contents of Mb. The result indicated that banana leaves may be a good substrate for nutritionally beneficial mushrooms.