Propionibacterium sp. are Gram-positive anaerobic rod-shaped bacteria. Although rarely pathogenic, under certain conditions these species can cause abscesses in various tissues. We report the case of a woman with one a 1-month history of right mammary pain, localized erythema and a palpable mass. Mammography, ultrasonography and core needle biopsy were performed. A retroareolar abscess was diagnosed and breast cancer was excluded. Surgical drainage was performed and tissue cultures revealed Propionibacterium sp. The patient was treated with doxycycline. Propionibacterium sp. are rarely found in breast abscesses and only a few cases have been reported. © 2009 SEGO.