The purpose of this study is to identify correlates of back problems and back disability in the adult population of the United States. Cross-sectional analyses were performed using data from the 1989 National Health Interview Survey (NHIS). Weighted polytomous logistic regression modeling was performed to estimate odds ratios adjusted for the effects of covariates. The prevalence of a disabling back condition, vs. no back condition, was relatively higher among subjects aged 25-64 years, male, non-high-school graduates, unemployed, living in the West, with disabling non-back morbidities, and with body mass index and weight above the 50th percentile. Among workers, those in technical, sales, clerical, private household, service, precision production and repair, or transportation occupations were relatively more likely to report disabling back conditions, compared to workers in professional occupations. Among adults with back problems, age greater than 34 years, weight above the 50th percentile, and history of back trauma were associated with chronic back disability. Although the magnitudes of the associations are not large, they may have enormous public health implications because of the high prevalence of back problems and related disability.