Abstract: Breast hamartomas are uncommon lesions that have not been extensively characterized in the adolescent population. A search of patient records at our institution over a 17-year period identified seven cases of breast hamartomas in patients less than 18 years of age. We examine and report the clinical, radiographic, and pathologic characteristics of these cases. Breast hamartomas present as painless, palpable masses in the adolescent population. Ultrasonography reveals a well-defined, solid, oval mass, similar to the more common fibroadenoma. Two of the patients underwent core needle biopsy for diagnosis as the only intervention with the remainder undergoing surgical excision. None of the patients had any complications from surgery. There was one recurrence 9 months after initial excision. Histologically, the hamartomas consisted of densely packed, enlarged lobules set within a fibrous stroma. Breast hamartomas are rare in the adolescent population. The clinical and radiographic features are similar to the more common fibroadenoma, but the pathologic findings are diagnostic. Recurrence can occur if excision is incomplete. Increased recognition and accurate diagnosis will improve our understanding of the natural history of these lesions.