The acute and subchronic toxicity studies of Boerhavia diffusa (B. diffusa) leaves in albino mice and rats were investigated. Phytochemical analysis was also carried out. 500, 1000 and 2000 mg/kg of the aqueous leaf extract were administered orally to the test groups while distilled water was given to the control group. The parameters measured include food and fluid intake, body weight, absolute and relative weight of various organs, haematological parameters [total white blood cell (WBC) and packed cell volume (PCV)], and tests for liver function: glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), alkaline phosphatase and total bilirubin. The lethal dose (LD 50 ) was found to be greater than 2000 mg/kg (p.o.) in both mice and rats. Rats treated with the extract had progressive increase in body weight, which was significantly (p < 0.05) different from control. The aqueous extract of B. diffusa leaves increased both food and fluid intake. There were no significant changes in both the absolute and relative organ weights between the control and the test groups. The liver enzymes and haematological parameters were statistically equal in all the groups. B. diffusa aqueous leaf extract is non toxic in albino rats.