Fifteen cases of herpes zoster with lower motor neurone paresis involving the upper and lower limbs are reviewed. Five patients had an underlying disease--three had rheumatoid arthritis, two of whom were on prednisolone; one had chronic lymphatic leukaemia and one lymphosarcoma. Details are given of the time relationship between onset of pain, the appearance of the skin eruption and the later muscle weakness. Electromyographic evidence was available in 12 patients. The difficulty of assessing the muscle power in the presence of severe pain is discussed. Prognosis was generally very good; 11 patients recovered fully, three improved and one was unchanged after 5 months, when he died of lymphosarcoma. One patient was lost to follow-up at 5 months but was improving at the time.