In a recent randomized clinical trial using buprenorphine (2 and 6 mg) and methadone (35 and 65 mg), we compared low-level opiate withdrawal symptoms among Whites (n = 84), Hispanics (n = 20), and African Americans (n = 21). During the first 2 months of opiate stabilization, persistent low-level opiate withdrawal symptoms were significantly lower in African-Americans and Hispanics than in the white patients. As expected pharmacologically, this relative underreporting of low-level withdrawal by minority patients was greater for the low opiate doses (buprenorphine 2 mg and methadone 35 mg). This underreporting may reflect sociocultural as well as biological differences, because subjective, but not objective, withdrawal symptoms showed this ethnic difference.