The occurrence of lipomas following trauma is reported in three cases with a review of the literature including 36 additional cases. This condition is usually related to massive trauma in the hip, buttock, and thigh area that is most frequently secondary to a motor vehicle accident. It is most common in the female and may be attributed to the characteristic hip, buttock, thigh fat deposition of the female. The "tumor" usually follows heavy bruising and/or hematoma of the region and is clinically noticeable approximately 6 months thereafter. Initial treatment is preventive by drainage of the hematoma and compression of the site. Late treatment is surgical excision of the tumor.