The aim of this study is to investigate the serum levels of parathyroid hormone (PTH), calcitonin, 1,25 (OH)(2) vitamin D3, estradiol and testosterone in male patients with active renal calcium stone disease compared with controls and investigate their relationship with serum/urinary biochemistry. Male active renal calcium stone formers (ASF) were enrolled from December 2008 to April 2009. Controls were selected from age and sex matched individuals. Two 24-h urine samples and a blood sample were withdrawn from each participant while they were on free diet. Serum 1,25 (OH)(2) vitamin D3 levels in the ASF and control groups were 127 ± 40 and 93 ± 35 pmol/l (p < 0.001). Serum levels of PTH, calcitonin, estradiol and testosterone were not statistically different between the ASF and control groups (all p > 0.05). Serum 1,25 (OH)(2) vitamin D3 was associated with higher urinary excretion of calcium and phosphorus in ASF patients. Serum levels of calcitonin were related to less urinary excretion of calcium in the control group. Serum testosterone was related to higher urinary excretion of uric acid in ASF patients and to higher urinary excretion of oxalate in the control group. 1,25 (OH)(2) Vitamin D3 is an important hormone in the pathogenesis of recurrent renal calcium stone disease and could increase renal stone risk by increasing the urinary excretion of calcium and phosphorus. There is a possibility of testosterone involvement in the pathogenesis of renal stones through higher urinary uric acid and oxalate excretion.