Elastofibroma dorsi is a slowly growing tumour-like process composed of an ill-defined mass of fibro-elastic tissue. It occurs almost exclusively in the elderly and is thought to result from mechanical friction. It has received little attention in the radiological literature and is considered a rare lesion. With indications for computerised imaging expanding, elastofibroma dorsi will probably be seen more frequently. This report describes an elastofibroma presenting in an 11-year-old girl and its appearance by magnetic resonance imaging. Presumptive diagnosis by magnetic resonance imaging may prevent unnecessary radical surgery.