Abstract: Tetrapleura tetraptera fruit is widely used in Western Nigeria amongst men as a birth control medicine. It has been reported that feeding of extracts to animals produced some toxic effects and pathological lesions in some organs. This study was designed to investigate the haematological effects of 10 days oral administration of the ethanolic extract of Tetrapleura tetraptera (TTE) fruits in mature male rabbits. Twenty healthy acclimatized male rabbits (1.4-1.6 kg b.wt. were randomly assigned to 4 groups. Animals in groups 2, 3 and 4 were administered 50, 100 and 150 mg kg-1 b.wt. of TTE. Animals in group 1 served as the control and received only water and no extract. All animals were fasted for 18 h after withdrawal of treatment and sacrificed after anaesthesia. Venous blood sample from groups were analyzed for haematological parameters. The TTE caused significant (p<0.05) reduction in RBC and WBC.