Aging influences bone resorption and formation. There is a strong correlation between decreased melatonin (MEL) levels and the increased incidence of bone deterioration. The aim of the present work was to examine MEL on blood and bone minerals contents. Twenty female rats (24 months old) were divided into two equal groups, vehicle-treated control and MEL treated (subcutaneous injection of 50 μg/100 g b.w MEL). After 14 weeks of treatment, blood and bone samples were collected. Serum total and bone specific alkaline phosphatase (TALP and BALP), corticosterone, nitrite (NO), malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) activity and serum and bone calcium ( Ca), zinc (Zn), copper (Cu), iron ( Fe) and manganese (Mn) were determined. There was a significant (P<0.01) increase in bone mass, BALP and SOD activities and GSH in MEL treated rats. Moreover, a significant (P<0.05) increase in serum Ca level and serum and bone Zn and Fe and significant (P<0.05) decrease in serum NO, MDA and corticosterone level in treated group was observed. In conclusion, long-term melatonin treatment has a positive impact in preventing aging related bone degradation and lipid peroxidation.