To estimate the prevalence of carpal tunnel syndrome among US adults, data from the Occupational Health Supplement of the 1988 National Health Interview Survey were analyzed. Based on a sample of 44,233 households (response rate, 91.5%), an estimated 1.55% (2.65 million) of 170 million adults self-reported carpal tunnel syndrome in 1988. Females and Whites had a higher prevalence of self-reporting carpal tunnel syndrome than males and non-Whites, respectively. Among 127 million adults who worked during the 12 months before the survey, 0.53% (0.68 million) reported that their "prolonged" hand discomfort was called carpal tunnel syndrome by a health care provider.