A study was carried out to investigate the performance of Oyster mushroom (Pleurotus ostreaatus) on some tropical trees at NIHORT, Ibadan in 2009. The tropical trees evaluated were mango (Mangifera indica), coconut (Cocos nucifera), neem (Azadirachta indica), acacia (Acacia species) and their mixed bed. The experiment was laid out in completely randomized design with 3 replicates. Observations were made for the growth and yield of the mushroom. In this study, Pleurotus ostreatus performed best on mango in terms of fruit number (36), fruit weight (138.33g), width of pileus (5.23 cm) and length of stipe (4.50cm). it also produced the highest biological (79.05%) and production (32.78%) efficiencies respectively. Coconut produced the least fruit number (8), fruit weight (29.73g), width of pileus (3.6 cm) and length of stipe 3.23cm). Its biological and production efficiencies are 17.00% and 7.09% respectively. The highest mycelia extension from mango (16.27cm), while acacia (8.17cm) produced the least mycelia extension. These findings suggested that mango tree is suitable for mushroom cultivation when used as a substrate.