Spontaneous infarction is an uncommon complication occurring in fibroadenoma of the breast. Although infarction following fine-needle aspiration has been reported in the literature, to the best of our knowledge this is the first reported case where infarction was encountered on first-time aspiration. It is necessary to distinguish infarcted fibroadenoma from mastitis, duct ectasia, mammary tuberculosis, and carcinoma on cytology smears. Lack of knowledge of this entity may lead to an erroneous diagnosis of inflammatory lesion or carcinoma. We report the first case of cytological and histological findings in spontaneous infarction of fibroadenoma in 13-yr-old female.