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Abstract Background: Prevalence of urolithiasis is increasing in children and maybe hematury is only sign. This study was conducted to investigate clinical manifestation and etiology of urolithiasis in children younger than 14 year-old. Materials and Methods: This descriptive and case-series study was carried out on 100 patients referring to Sahamie Pediatric hospital in Qom in 2007-8. Age, sex, family history, clinical manifestation (fever, dysuria and Pain) and laboratory tests (Na, K, Ca, P, urea, Cr, Albumin, Alkaline phosphates of serum ABG, urine sediment, urine culture Na, K, Ca, P, Cr, oxalate and citrate of urine/24h and cysteine in random sample of urine) were determined. Ceratenin correcting formula was used for adequacy controlling of urine collecting. Results: Hypocitraturia (56.8%), hypercalciuria (29.4%), hyperuricosuria (26.3%), hyperoxaluria (14.7%), phosphaturia (8.4%) and cystinuria (6.3%) were detected. Also, 54% patients had urinary tract infection. Pain (27.7%), fever (33.3%), irritability and dysuria (62.2%) and hematuria (77.7%) were seen. Positive family history was reported in 23% of patients. Conclusion: Most common clinical manifestations in children with stone were hematuria, dysuria, fever and pain. The common etiology of urolithiasis respectively was hypocitraturia, hypercalciuria, hyperuricosuria, hyperoxaluria, phosphaturia and cystinuria.