This study was conducted to compared phytochemical analyses of methanolic and aqueous leaf extracts of three medicinal plants used in plant disease control. Phyllanthus discoideus, Phyllanthus amarus and Phyllanthus muellerianus. The phytohemicals were extracted from the parts of the three Phyllanthus species with methanol for qualitative and quantitative determination following standard procedures. The data obtained revealed the presence of alkaloids, flavonoids, tannins, saponins and phenols, although at varying levels in the various parts of the Phyllanthus species. Generally, most of the phytochemicals are of higher concentration either in the leaves or stems than in the roots of the Phyllanthus species, but phenols appeared to be very low in the various parts of these plants. The pooled data showed that, there were more tannins, saponins and phenols in the leaves than in the stems and roots, but more of alkaloids in the stems and flavonoids in the roots. The highest alkaloids, flavonoids, tannins and phenols were extracted from Phyllanthus muellarianus while the highest saponins was extracted from Phyllanthus discoideus. The study showed the presence of alkaloids, saponins, flavonoids, tannins and phenols in all the Phyllanthus species, but at varying concentrations in the various species and their parts. These differences in phytochemical levels would likely confer unique medicinal potentials on the various parts of each of these species.