The acute toxicity of the aqueous leaf extract of C .grandiflora, a climbing shrub found mainly in the adjacent regions of Coimbatore, Nilgiry and Tir uchirappalli, South India was investigated. For the acute toxicity study, 1000-3000 mg/kg of th e aqueous leaf extract were administered to rats and obvious toxic symptoms and mortality 24 ho urs postadminstration of the extract were determined. However, the initial reactions included excitement, tremors, and restlessness, loss of appetite and general weakness .No muscular numbness of the hind and fore legs, salivation or diarrhoea was observed .The symptoms were dose depe ndent with signs noticeable with increasing dosage. Post mortem, haematological and histopathological examination did not show any significant (P<0.05) damage as a result of the extract administration. No significant changes in body weights of treated rats were observ ed when compared with untreated control groups Phytochemical screening of the aqueous stem bark extract revealed the presence of cardiac glycosides, flavonoids, saponins, and tanni n. The results suggest that the aqueous extract is not acutely toxic to the mice.