Clerodendrum phlomidis Linn. has been traditionally used for treatment of gynecological disturbances and for agricultural uses. It has been used in many Ayurvedic polyherbal formulations as an immunomodulatory agent. Irrespective of its widespread use, no data on subchronic toxicity has been described. The present study was designed to access sub-chronic toxicity of aqueous extract of Clerodendrum phlomidis leaves. Aqueous extract of Clerodendrum phlomidis leaves was given orally at doses of 200, 400 and 800 mg/kg/day for 90 days for the evaluation of sub-chronic toxicity study. General behavior, mortality, animal body weight, food and water consumption were observed throughout the study period. Hematological, biochemical parameters and histopathological analysis were done at the end of study period. No mortality and abnormal behavior was observed in rats exposed to all the three dose levels. Highest dose produced significant decrease in the red blood cell, hemoglobin and increase in white blood cell count. Biochemical parameters like triglycerides, bilirubin, creatinine and total proteins were significantly altered at high dose. Histopathological findings revealed architectural changes in the liver and kidneys with high dose.