We report a case of subacute myopathy in a 47 years old man engaged on boiler maintenance at an oil-fired thermoelectric power station. The occupational history highlighted heavy exposure to inhalation of ash derived from mineral oil combustion and containing several elements, metals and metalloids, including vanadium and nickel. The presenting symptoms, clinical course and muscle histopathology suggest that exposure to toxic agents probably played an important part in the causation of the myopathy.