Abdominal mass is one of the commonest clinical findings in children. The purpose of this study was to evaluate abdominal masses in different age groups in a referral children surgical center. We retrospectively reviewed records of 325 patients (57% boys, mean age 37.7 months) admitted to Amir Kabir hospital in period of 12 years for abdominal mass surgery. The 4 most common abdominal masses was Wilm's tumor (22.4%), abdominal lymphoma (13.5%), neuroblastoma (12.5%) and hydronephrosis (12.3%). These masses composed 60% of abdominal masses and the remaining were: Hydatid cyst of liver, ovarian masses, liver masses, choledochal cyst, mesentery and omental cyst, etc. This results were found to be similar with little differents to results of other centers.
