Introduction: leaves and seed oil of Prinsepia utilis Royle are traditionally used for rheumatism, pain, arthritis, bone disorders and joint ailments. This study was designed to investigate the anti-oxidant effect and anti-osteoporotic potential of Prinsepia utilis Royle in ovariectomized female rats. Methods: Female Wistar rats (180-200 g) were divided into 6 different groups (n = 5 per group). Acute toxicity studies were carried out as per the OECD 423 guideline. Osteoporosis was induced by surgical ovariectomy model. The phytochemical screening and in vitro anti-oxidant activity using DPPH assays of Prinsepia utilis Royle extracts were also carried out. Results: Surgical removal of ovaries caused pathological changes similar to osteoporosis. P. utilis extracts 50, 100 and 200 mg/kg produced a significant increase in bone density, bone strength, alkaline phosphatase activity, serum calcium, serum phosphorous and a decrease in urine hydroxylproline levels, as compared to ovarectomised control rats. The phytochemical screening of P. utilis extract revealed the presence of flavonoids, tannins, terpenoids, beta-sitosterol and ursolic acid. DPPH assay showed prominent free radical scavenging potential of the methanolic extract. Conclusion: The findings suggest that the leaves of the P. utilis Royle have marked protective effect against induced osteoporosis and improved bone quality, attenuated bone resorption, enhanced the rate of bone formation and restored bone density. This may provide evidence for the pharmacological basis for its therapeutic traditional uses. (C) 2014 Elsevier GmbH. All rights reserved.