Administration of an extract from the plant Withania somnifera (Family: Solanaceae) (20 mg/dose/animal; i.p.) for five days along with cyclophosphamide (CTX) (1.5 mmol/kg body wt. i.p.) reduced the CTX induced urotoxicity. Morphological analysis of the bladders of the CTX-treated group showed severe inflammation and dark coloration whereas CTX along with the Withania-treated group showed normal bladder morphology. The extract was found to reduce the protein level in the serum (7.92 g/l) after 4 h of CTX treatment, which was higher in the CTX alone-administered group (11.44 g/l). Blood urea N2 level which was drastically enhanced (136.78 mg/100 ml) 2 after the CTX treatment was significantly reduced (52.08 mg/100 ml) when the animals were treated with Withania extract. Similarly the glutathione (GSH) content in both bladder (1.55 micromol/mg protein) and liver (3.76 micromol/mg protein) was enhanced significantly (P<0.001) in the Withania-treated group compared with the CTX alone-treated animals (bladder 0.5 micromol/mg protein; liver 1.2 micromol/mg protein) Histopathological analysis of the bladder of CTX alone-treated group showed severe necrotic damage where as the Withania somnifera-treated group showed normal bladder architecture.