Moringa oleifera plant has been reported to have antioxidant properties which aroused the search for its radioprotective effects.This study is expected to highlight the possible prophylactic role of aqueous extract of Moringa oleifera leaves following exposure to radiation.A total of 90 Wistar rats were divided into six groups of fifteen rats each. Theseare: group 1 (control without radiation or moringa extract), group 2 (50 mg/kg b. wt. of aqueous extract of M. oleifera), group 3 (100 mg/kg b. wt. of aqueous extract of M. oleifera leaf), group 4 (2.5 Gy of gamma radiation only), group 5 (50 mg/kg b. wt. of M. oleifera + 2.5 Gy of gamma radiation), group 6 (100 mg/kg b. wt. of M. oleifera + 2.5 Gy gamma radiation).Two hours after the final administration on the fifth day, selected rats were exposed to a single dose of 2.5 Gy gamma radiation. The animals were sacrificed at on days 2, 7 and 14 after irradiation. Exposure to the 2.5 Gy showed significant decrease in the WBC, PLT, RBC, HGB, LYM while no significant changes was noted in the MCV throughout the three timelines used for this study. However, pre-treatment with aqueous extract of M. oleifera leaves was observed to reduce these detrimental effects. Thus, aqueous extract of M. oleifera leaves has the prophylactic potency to help reduce radiation damage to the haematopoietic system.