The phytochemical compositions and vitamins contents of the fruit bodies of Pleurotus pulmonarius grown on different barks of fruit trees namely; Treculia africana (TA), Mangifera indica (MI), Dacryodes edulis (DE), Pentaclathra macrophylla (PM) and Elaeise guineensis (EG), supplemented with agro-wastes (Maize cobs, Fluted pumpkin wastes and Yam peels) were determined. Data obtained from these were subjected to ANOVA in a CRD and replicated 3 times with different levels of supplement per replicate. There was significant differences (p<0.05) within vitamin compositions of the fruit-bodies of Pleurotus pulmonarius produced in the various substrates. The values ranged from 0.029% of vitamin B1 in DE and EG (80%) to 0.89% in PM (40%), vitamin B2 (0.16% in DE (80%) to 0.56% in TA (60%), vitamin B3 (0.29% in TA (60%) to 0.95% in PM (40%), vitamin c (5.34% in PM (60%) to 7.82% in MI (80%).The fruit bodies of Pleurotus pulmonarius also contained different levels of phytochemicals which ranged; alkaloids (0.039% in TA (60%) to 0.094% in DE (60%), phenols (0.004% in TA (60%) to 0.06% in PM and EG (80%), Tannins (0.13% in MI(60%) to 0.85% in DE (60%), saponins (0.16% in PM (40%) to 0.43% in EG (40%), flavonoids 0.015 in MI (80%) to 0.53% in TA (40%) and sterols (0.015 in MI (80%) to 0.031 in TA (80%).Tropical mushrooms especially P. pulmonarius are rich in vitamins and phytochemical compositions. Attempts should be made to explore this species of Pleurotus commercially in Nigeria.