Assessed the effectiveness of electromyographic (EMG) and skin-temperature (ST) biofeedback and relaxation training (RT) in reducing the aversiveness of cancer chemotherapy. Eighty-one cancer patients, equated on several individual-difference variables, were randomized to one of six groups formed by a 3 (EMG Biofeedback, ST Biofeedback, No Biofeedback) x 2 (RT, No RT) factorial design. Outcome was assessed with physiological, patient-reported, and nurse-reported indices taken over five consecutive chemotherapy treatments. RT patients showed decreases in nausea and anxiety during chemotherapy and physiological arousal after chemotherapy. EMG and ST biofeedback reduced some indices of physiological arousal but had no other effects on chemotherapy side effects. These findings suggest that RT can be effective in reducing the adverse consequences of chemotherapy and that the positive effects found for biofeedback in prior research were due to the RT that was given with the biofeedback, not to the biofeedback alone.