The cause of Dupuytren's disease is unknown, but inflammatory cells might have a role. Enzymatic digestion of diseased tissue permits identification and immunofluorescent labelling of a cell subset displaying inflammatory cell morphology. Cytofluorimetry of this cell population demonstrated the presence of CD3-positive lymphocytes and expression of major histocompatibility complex (MHC) class II proteins. These results raise the possibility that Dupuytren's disease is a T-cell-mediated autoimmune disorder. The development of medical treatment on this basis may reduce the need for surgery, with its associated morbidity and high recurrence rates.