---

Background: Regarding the significance of abdominal masses in children, we aimed to identify the pathology of masses according to the age and sex groups. Materials and Methods: We retrospectively reviewed pathological reports of 461 patients with abdominal mass that underwent resection or biopsy during the study period (25 years). Results: One hundred and eighty six cases (40%) were non-neoplastic, many of which had renal originand 35 cases (7%) were hydatid cysts. Concerning the 271 neoplastic masses (58%), 96 cases (20%) were diagnosed as renal tumors (frequently Wilm’s tumor), 63 (13%) as neuroblastoma and 56 (12%) as abdominal lymphomas. Conclusion: Abdominal masses in children coming to a referral pediatric surgery center are more likely to be neoplastic. We also found that malignancies are rare in neonatal period in comparison to other age groups. Keywords: Abdominal mass, neoplastic, hydatid cyst, wilm’s tumor, neuroblastoma