Mammary-type myofibroblastoma is a very rare, benign, spindle cell lesion, arising mainly in the inguinal region. This clinical entity strictly duplicates the features of its breast counterpart. To our knowledge, this is the first report of this particular lesion occurring in the popliteal fossa. We discuss the clinical, radiological and histopathological features of this case, emphasizing the role of incisional biopsy in such an unusual neoplasia.