A source of data on the health and working conditions of a probability sample of United States workers, the Quality of Employment Survey for 1972-3 (QES73), is investigated for the first time to determine which groups of workers are more or are less likely to report back pain. Estimated coefficients from a logistic regression are used to calculate odds ratios and confidence intervals for various groups. Few previous studies on back pain among United States workers control for as many potentially confounding variables as are considered in this study and few use data from a national probability sample of workers. The following independent variables are judged to be important positive correlates based on their estimated odds ratios and confidence intervals: farm, service, blue collar, and clerical work; low levels of schooling and income; jobs needing physical effort; age between and including 50 to 64; and smoking. Marital separation was found to be negatively correlated with back pain. Caution should be exercised in attempting to generalise these findings, since the back pain variable is based on respondents' subjective evaluations. Moreover, the variable does not distinguish between lower or upper back or neck pain, nor is information on the duration or frequency of pain available.