Elastofibroma dorsi (EFD) is a rare, benign, soft tissue tumor with an unclear pathogenesis, typically localized to the subscapular region. It occurs within the periscapular area between the ribs and dorsal chest wall muscles. Repetitive microtrauma by friction between the lower part of the scapula and the thoracic wall may cause reactive hyperproliferation of the fibroblastic tissue. This view has been supported by the higher prevalence of EFD, particularly among individuals who perform hard manual labor. EFD can, however, also be observed in those who have never performed hard manual labor and particularly in women over the age of 50. In this report, we present a case of bilateral EFD in a 52-year old woman with bilateral hypermastia, and examine the possible correlation between hypermastia and EFD.