['Studies of prostitution have focused largely on individuals involved in the commercial sex trade, with an emphasis on understanding the public health effect of this behavior. However, a broader understanding of how prostitution affects mental and physical health is needed. In particular, the study of prostitution among individuals in substance use treatment would improve efforts to provide comprehensive treatment.', 'To document the prevalence of prostitution among women and men entering substance use treatment, and to test the association between prostitution, physical and mental health, and health care utilization while adjusting for reported history of childhood sexual abuse, a known correlate of prostitution and poor health outcomes.', 'Cross-sectional, secondary data analysis of 1606 women and 3001 men entering substance use treatment in the United States who completed a semistructured intake interview as part of a larger study.', 'Self-reported physical health (respiratory, circulatory, neurological, and internal organ conditions, bloodborne infections) and mental health (depression, anxiety, psychotic symptoms, and suicidal behavior), and use of emergency department, clinic, hospital, or inpatient mental health services within the past year.', 'Many participants reported prostitution in their lifetime (50.8% of women and 18.5% of men) and in the past year (41.4% of women and 11.2% of men). Prostitution was associated with increased risk for bloodborne viral infections, sexually transmitted diseases, and mental health symptoms. Prostitution was associated with use of emergency care in women and use of inpatient mental health services for men.'] Does prevalence and health correlate of prostitution among patients entering treatment for substance use disorders?