The clinical and histological features of 'mechanic's hands' are described in a patient with polymyositis characterized serologically by antibodies to histidyl tRNA synthetase (Jo-1). Although described in the past in association with polymyositis, these distinctive cutaneous lesions have only recently been associated with the 'anti-synthetase syndrome'. It is becoming apparent that recognition of subsets within the spectrum of polymyositis/dermatomyositis characterized by certain clinical and serological features not only have prognostic significance, but also may provide insights into mechanisms of disease.