Four organic wastes; mahogany (Khaya ivorensis) sawdust (MSD), Gmelina aborea sawdust (GSD), oil palm fruit fibre (OPFF) and oil palm empty fruit bunch (OPEFB) were evaluated for their effects on growth, yield, quality and protein content of Lentinus squarrosulus (Mont.) Singer. Plastic bag technology was used with treatments replicated ten times and arranged using a completely randomized design. The quality of the harvested mushrooms was evaluated on the basis of four pileus diameter size groups (>7 cm, 5-7 cm, 3-5 cm, <3 cm) and a deformed group; while their protein analyses were carried out using Kjeldahl’s method. Results on mushroom growth showed that oil palm fruit fibre (OPFF) took the least time for full mycelial colonization and the longest time occurred on Gmelina sawdust (GSD).