Background: Cleistopholis patens (Cp) (Annonacae) is a popular medicinal herb used in the the treatment of cardiovascular disorders in Nigerian ethnomedicine. Objectives: The present study investigated the effects of the aqueous leaf extract of Cp on lipid and haematological profile of hypercholesterolemic Albino rats. Methods: The animals were divided into 5 groups (A – E) of 5 animals per group. All the animals in groups A – D, along with their normal diet, also received 400 mg/kg of cholesterol suspended in 2 % Tween 80 (p.o) daily for 60 days. Six hours after each cholesterol feeding, the animals were treated respectively with a hypolipodemic drug, simvastatin; 10 mg/kg, C. patens extract; 400 mg/kg, 600 mg/kg and 2 % Tween 80 (negative control). The last group (positive control) received cholesterol free diet and 2 % Tween 80. All the treatments were administered orally for a period of 60 days. Thereafter, the lipid and haematological profile of serum and blood samples collected were determined respectively. Results: Treatment with simvastatin (10 mg/kg), the extract (400 and 600 mg/kg) significantly (P =0.033) lowered the total cholesterol, triglycerides, low density lipoproteins (LDL) levels and significantly (P =0.05) increased the level of high density lipoproteins (HDL) in comparison with the negative control group. There was no significant difference between the cholesterol lowering effect of the extract and that of simvastatin (P =0.991). The haemoglobin concentration, packed cell volume, red and white blood cell counts of treated animals did not produce any significant change (P =0.705). The LD50 showed that the extract has a wide margin of safety. Conclusion: The extract showed marked hypolipidemic activity.