Previous studies have shown that acupressure bands can reduce chemotherapy-related nausea. Patients' expectations of efficacy account for part of this outcome. We conducted a three-arm randomized clinical trial to investigate the effectiveness of acupressure bands in controlling radiation therapy-induced nausea and to test whether an informational manipulation designed to increase expectation of efficacy would enhance the effectiveness of the acupressure bands. Patients who experienced nausea at prior treatments were randomized to either standard care (Arm 1, n=29) or standard care plus acupressure bands with either neutral (Arm 2, n=30) or positive (Arm 3, n=29) information regarding the efficacy of the bands. Patients reported nausea for two days prior to randomization (baseline) and for five days following using a seven-point semantic rating scale (1=not nauseated to 7=extremely nauseated). Patients in Arms 2 and 3 combined reported greater reduction in average nausea than patients in Arm 1 (P=0.01; mean(bands)=0.70, mean(no bands)=0.10). This equates to a 23.8% decrease in nausea in the band groups compared to a 4.8% decrease in the control group, a 19% difference. The informational manipulation failed to alter efficacy expectations and there was no statistically significant difference in nausea between patients in Arms 2 and 3. Acupressure bands are an effective, low-cost, nonintrusive, well-accepted, and safe adjunct to standard antiemetic medication. An attempt to boost the efficacy of the acupressure bands by providing positive information was not successful.