Hypnosis was compared with nonhypnotic behavioral techniques for efficacy in reducing pain and anxiety in 27 children and adolescents during bone marrow aspiration and in 22 children and adolescents during lumbar puncture. The patients and independent observers each rated (scale of 1 to 5) pain and anxiety during one to three procedures prior to intervention and one to three procedures with intervention. Prior to intervention for both groups, pain during bone marrow aspiration was rated as more severe (P less than 0.01) than pain during lumbar puncture. During bone marrow aspiration pain was reduced to a large extent by hypnosis (P less than 0.001) and to a smaller but significant extent by nonhypnotic techniques (P less than 0.01), and anxiety was significantly reduced by hypnosis alone (P less than 0.001). During lumbar puncture only hypnosis significantly reduced pain (P less than 0.001); anxiety was reduced to a large degree by hypnosis (P less than 0.001) and to a smaller degree by nonhypnotic techniques (P less than 0.05). Thus hypnosis was shown to be more effective than nonhypnotic techniques for reducing procedural distress in children and adolescents with cancer.