This study evaluates the haemopoietic effect of Moringa oleifera aqueous roots extract on chickens. Six hundred grams (600g) of fresh Moringa oleifera roots was collected, washed, air dried, pulverized and aqueous extracted. The aqueous roots extract was further subjected to chemical extraction with chlorofoam, ethyl acetate and n-butanol chemicals based on their order of polarity. The root extract also underwent qualitative chemical screening for identification of the various classes of active chemical constituents of the plant root material. It was found to contain carbohydrates, Saponins, cardiac glycosides, Terpenes, steroids, Flavonoids and alkaloids in various concentrations. The ethyl-acetate portion which has the highest level of concentration of the constituents and thus was used for sub-acute toxicity studies in chickens. In the sub-acute studies, haematological parameters showed that the extract stimulated significant increase in red blood cells (RBC), white blood cells (WBC), hemoglobin concentration (Hb) and packed cell volume (PCV). This erythropoietic activity of the extract is an indication that M. oleifera aqueous roots extract have the capability of preventing anaemia in chicken and boosting the immune system.