Primary bladder stones (PBS), once very frequent in children, almost disappeared in developed countries. Although the same trend is observed in Armenian children, PBS is still an important group. Data from 198 patients with urolithiasis admitted to Arabkir Medical Centre in years 1992-2002 was evaluated. 18 of them with vesical stones were considered to have PBS because of large size and the absence of lithiasis or gross abnormalities of the upper urinary tract. Patients with PBS were considerably younger than those with renal stones. There was a clear male preponderance in both groups of patients. PBS were composed of calcium oxalate (72%), uric acid (22%) and ammonium acid urate (6%) as revealed by infrared spectroscopy. All stones were removed by open surgery. Recurrence of urolithiasis was not seen even in a single case of PBS during 10 year follow-up period.