Pediatric urolithiasis is an endemic disease, especially in certain developing regions of the world, such as the Far East, and to a certain extent the Middle East and Turkey. The aim of the study is to determine the metabolic etiology and the prevalence of formation of urinary calculi in Turkish pediatric patients with urolithiasis. Seventy-two pediatric patients diagnosed as having urolithiasis were studied from 1999-2005 in Dr. Behcet Uz Child Disease and Surgery Education and Research Hospital Nephrology Department, Izmir, according to their presenting signs and clinical and laboratory findings. The other necessary tests were also applied to detect the etiology of the calculi formation. Of the 72 patients, 50 (69.4%) were male and 22 (30.6%) were female, with ages ranging from 2 to 168 months (mean age 72 +/- 35.7 months), and the male-to-female ratio of patients was 2.3. Twenty-four (33%) of them were diagnosed as having metabolic urolithiasis, 21 (30%) anatomic, 19 (26%) infectious and 8 (11%) idiopathic. The age at which urolithiasis was first diagnosed was found to be low in the metabolic and anatomic etiology groups (P = 0.028). Thirteen patients (18%) with urolithiasis were known to have a family history of stone disease, and in all of them metabolic etiology was considered to be the reason (P < 0.001). In all of the groups, the localization of the stone was found to be the upper urinary system most of the time, and in 17 (24%) with bilateral multiple stones, the etiology was found to be metabolic (P < 0.001). All of the patients were followed up for 3-72 months (mean 29.2 +/- 13.7 months), and four of them (5.5%) had recurrences. In order to prevent renal damage and recurrences in pediatric patients with urolithiasis in Turkey in whom the etiology is mostly metabolic, the illnesses must be investigated very cautiously, and their early diagnosis and treatment modalities must be considered.