Accessory breast tissue is an uncommon condition which occurs in 0.4-6% of women. It is mostly located in the axilla and has a high incidence of being misdiagnosed. Usually it is bilateral and presents as an asymptomatic mass during pregnancy or lactation. The diagnosis of ectopic breast tissue is important as it can undergo the same pathological changes that occur in a normal breast, such as mastitis, fibrocystic disease and carcinoma. We present a case of a bilateral axillary localization of accessory breast in a 45-year-old woman. The principal symptom was pain and the clinical diagnosis was bilateral lipoma. However, subsequent imaging and histopathological examination proved it to be an accessory breast tissue.