The authors compared the effect of plasma exchange therapy on the need for nursing care for 26 patients with acute idiopathic Guillain-Barré syndrome. The patients were randomized either to a plasma exchange (PE) or conservative treatment group. The need for nursing care and the need for specialist nursing services was assessed daily by the nurses at the Department of Neurology. At first, the average need for care was the same for the two groups of patients, but the pattern of care over time was different, with the PE group needing more care at the beginning and then very much less care, whilst the conservative group needed a more uniform amount of care over the entire stay at hospital. In the PE group the need for specialist nursing services increased markedly, and the need for nursing care decreased rapidly after the first 2 weeks to a level lower than that needed by control group patients, probably because PE increased muscle forces of patients. This study suggests that PE treatment is useful in reducing patients' needs for nursing care, especially after the first 2 weeks following the treatment.