ABSTRACT; Background: Osteoporosis is usually associated with inflammation and increased oxidative stress, artemisinin was documented to have anti-inflammatory and anti-oxidant effects. In this study we evaluated the potential prophylactic effects of artemisinin on ovariectomy induced osteoporosis in rats. Methods: Thirty two sprague-dawley female rats aged 3 months old were classified into 4 equal groups (8 rats each), 1st group was left without ovariectomy, 2nd group was subjected to ovariectomy operation and left without treatment for 3 months, 3rd group was subjected to ovariectomy operation then started oral alendronate (1 mg/kg/d) next first day after the operation and continued for 3 months, 4th group was subjected to ovariectomy operation and then started oral artemisinin (70mg/kg/d) next day after the operation and continued for 3 months. Serum samples were tested for tumor necrosis factor alpha (TNF-α) and cross linked telopeptides of type I collagen (CTX-І). Rat femurs of each group were subjected to histopathological examination by haematoxyline and eosin (H&E) staining. Results: Ovariectomized group showed increased serum level of both TNF-α and CTX-І. Alendronate treatment for 3 months reduced serum CTX-І, failed to decrease the increased serum level of TNF-α in ovariectomized rats and improved bone mineral density (BMD) as demonstrated by histopathological examination in comparison to control ovariectomized rat. Artemisinin treatment for 3 months reduced serum TNF-α, CTX-І and improved BMD as demonstrated by histopathological examination when compared to control ovariectomized rat. Conclusions: Artemisinin has a potential prophylactic effect against osteoporosis in ovariectomized rats which is comparable to that of alendronate effect.