Halofantrine hydrochloride (halfan) was administered via oral route to matured female wistar rats weighing 180-200 g. The Wistar rats were randomly selected and divided into six groups of four rats each, making a total of twenty four rats and coded A1, A2, A3, B1, B2 and B3. Groups A3 and B3 were used as controls. Three consecutive doses of 1 mg/100 g halfan each were administered to group A1 at six hourly intervals while three doses of 2 mg/100 g halfan each were administered to group A2 at six hourly intervals. The animals were sacrificed on the 5th day after drug administration by cervical dislocation. Animals in groups B1 and B2 were given doses corresponding to A1 and A2 respectively, but in addition drug administration was repeated the fifth day following the day of first administration. The animals in this group were sacrificed on the tenth day by cervical dislocation, the ovaries were removed, blotted dry, fixed in 10% formal saline for histological processing and studies. Histological changes observed in the ovary include retarded growth of follicles, reduction in size and number of follicles, increase in cytoplasmic vacuolation, constriction of blood vessels, absence of corpora lutae and cases of cellular necrosis. These alterations were more pronounced in those groups sacrificed on the tenth day.