Objective: The overwhelming majority of breast masses in children are benign. In this paper we aimed to evaluate the breast masses in children. Methods: All children younger than 18, who were diagnosed with breast mass and were admitted to our center between March 2012 and March 2014 were analyzed for age, gender, complaint, the history of malignancy, the localization of breast mass, sonographic and pathological findings, and the diagnosis, retrospectively. Results: Twenty-nine girls and 8 boys (age ranges from 5 to 18) were admitted to our center with breast mass within the last two years. Except for mass, 5 patients had pain, and 8 patients had nipple discharge. Two patients had family history of breast cancer. Three patients had an operation of mass excision. Histopathological diagnosis of two patients were juvenile fibroadenoma, and pseudoangiomatous stromal hyperplasia.Other diagnoses according to clinical and sonographic features were: Fibroadenoma 11, gynecomastia 8, breast abscess 6, premature thelarche 3, mammary duct ectasia 2, accessory breast 1, fibrocystic change 1 and adenosis 1. Patients were followed up with ultrasound and none of them developed malignacy. Conclusion: The prevalence of breast cancer in the pediatric age group is extremely low, so a conservative approach of clinical and sonographic followup is more commonly adopted in children.