Objectives: In this prospective study, the effect of calcitriol therapy on bone mineral density and osteopenia in patients with severe secondary hyperparathyroidism has been investigated. Materials and methods: The study was carried out on 24 chronic dialysis patients consisting of 13 boys and 11 girls, aged between 8-18 years. Patients were divided into 3 groups according to the severity of hyperparathyroidism and therapy regimens. Group I consisted of 5 patients with normal parathormon levels who did not receive calcitriol therapy. In group II and III, there were patients with secondary hyperparathyroidism. Group II consisted of 10 patients receiving oral calcitriol therapy. Group III consisted of 9 patients receiving intravenous (IV) calcitriol. Bone mineral density was measured by dual energy x-ray absorptiometry. Osteopenia was defined as a Z-score worse than -2. Bone mineral density was assessed as baseline and at the end of one year. Results: A significant improvement was observed in Z-score in the group III whereas the mean value of Z-score tended to be worse in group I and it was not significantly different in group II from the initial values. The better Z-score in group III was associated with more effective stabilization of alkaline phosphatase level and bone specific alkaline phosphatases (BAP) concentrations. Conclusion: Significant improvement of Z-score in group III suggested the beneficial role in IV administration of calcitriol in chronic dialysis patients.