This study evaluated the toxicological effects of chronic treatment with ethanolic extract of Waltheria indica aerial portion on body weight, hematological and biochemical parameters in albino rats using standard methods. Rats treated with 400 mg/kg body weight (bw)/day of the extract showed no behavioural changes. However, there was general reduction of activity in rats given 800 and 1,600 mg/kg bw/day of the extract. Also, the LD 50 treated rats exhibited hypoactivity, grooming, prostration and irritation during treatment in the third and fourth weeks of treatment period. The data on body weight changes indicated that there were no significant differences in body weight between the control group and groups that received different doses of the extract (p<0.50). Haematological results for the red blood cell, haemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration in extract treated rats showed no significant changes at all doses of treatments when compared with controls in female rats. However, data on mean corpuscular haemoglobin in the male rats treated with 1,600 mg/kg showed a significantly decreased value when compared with controls. On the other hands, white blood cell counts decreased significantly after treatment with 400 and 800 mg/kg bw/day extract in the male rats. Lymphocytes count was also decreased significantly in males treated with 800 mg/kg bw/day of extract. Alanine transaminase (ALT), total bilirubin and creatinine increased significantly, respectively at 800 and 1,600 mg/kg bw/day doses of extract when compared with the control rats (p<0.05). In conclusion, the overall data of this study suggest that the oral administration of W. indica extract did not induce any toxic effects, especially when administered at low doses; however, further investigation is needed to evaluate its chronic toxicity.