We have described the characteristic ultrasonographic features using high-resolution ultrasonography (US) in palmar fibromatosis or Dupuytren’s disease and plantar fibromatosis or Ledderhose disease. The author suggests that Dupuytren’s disease occurs at the distal metacarpal (MC) region of the fouth digit in the subcutaneous tissue of the hand. It is strongly suggested that gray-scale US provides the association of the lesion and the flexor tendon and that Real-Time Tissue Elastograhy (RTE) images reflect the estimation of elasticity alteration in palmar fibromatosis. Clinically and genetically, it may be important that plantar fibromatosis shoud be considered as a concomitant disease of palmar fibromatosis.