Haemophiliacs suffer considerable pain when they bleed into their joints. This study investigated the use of transcutaneous electrical nerve stimulation (TENS) for relief of such pain. Thirty-six haemophiliac patients received either active or placebo TENS treatment. The intensity of pain was assessed before and after treatment using the McGill Pain Questionnaire. After 25 min of active treatment, 71% of the subjects reported at least 50% pain relief as measured by the McGill Pain Questionnaire. This compares with only 25% pain relief experienced by the placebo group.