Fusarium oxysporum was found associated with the leaf spot disease of Zanthxylum zanthoxyloides. The goal of this study was to employ Moringa oleifera aqueous leaf and seed extracts to inhibit the development of F. oxysporum in vitro at doses of 100, 200, 300, 400, and 500 mg mL^-1. Tests for the presence of certain secondary metabolites were also carried out. Naturally occurring substances such as alkaloids, flavonoids, saponins, phenols, steroids, terpenoids and cyanoglycosides were identified in the samples. The extracts from the two parts of the plant were effective against the growth of F. oxysporum. The highest inhibitory effects of leaf extract occurred at 400 and 500 mg mL^-1, with a mean diametric measurement value of 0.57 cm and the least at 100 mg mL^-1 with a value of 1.28 cm.  Similarly, the highest effect of seed extract was at 500 mg L^-1 with a value of 0.76 cm and the least at 100 mg mL^-1 with 1.34 cm fungal growth as compared to1.92 cm fungal diameter recorded in the control treatment. This work shows that the test fungus could be controlled effectively using concentrations of 400 and 500 mg mL^-1 leaf and seed extracts of M. oleifera.