Abstract: The aim of this study was to investigate the short- term toxicological effects of Simulated Bitumen Leachate (SBL) on white rat. Changes brought into the haematological and biochemical parameters of the rats by the SBL were measured and used as indices of toxicity. Simulated bitumen leachate of Agbabu natural bitumen was prepared by stirring 150 g of the bitumen in 4 liters of bore-hole water for eight weeks. Some of the physicochemical properties of the SBL include Biochemical Oxygen Demand (BOD) 103.43±0.56 mg L-1, total petroleum hydrocarbon (TPH) 327.89±0.23 mg L-1, pH 7.42±0.04, Chemical Oxygen Demand (COD) 500. 64±0.65, SO42¯ 490.27±0.47 and NO3¯ 96.37±0.32 mg L-1. Various concentrations (0, 25, 50, 75, 100% v/v) of the SBL were included in the ration of the rats. Treatments were arranged in a randomized design of 5 treatments with 2 replicates each and rats were observed for 2 weeks. Haematological parameters including White Blood Cells (WBC), Red Blood Cells (RBC) and Packed Volume Cells (PVC) were higher in rats fed with SBL supplemented feed ration compared to untreated rats (p<0.05). Similarly, statistical analysis of biochemical parameters of treated and control rats revealed significant differences (p<0.05). These results have a very negative implication on the health status of the rat. It thus implies that the simulated bitumen leachate is toxic to white rat.