Background and Objectives: The purpose of this study was to examine the associations between alcohol and drug abuse and risky sexual practice in a sample of 366 driving under the influence (DUI) offenders. Study Design: Data were collected from a sample of participants at a university-operated drunk driving intervention program. Specific indicators included established or severe alcohol/drug use problems, multiple drugs used, multiple alcohol/drug related arrests, and early regular alcohol use. Multiple sexual partners, condom use, and having sex while under the influence of alcohol or drugs were used to measure risky sexual behavior patterns. Correlation and logistic regression analyses examined associations between these substance abuse and sexual risk taking measures. Results: Substance abuse in general was unrelated to risky sexual behavior such as multiple sexual partners or lack of condom use. However, having sex while high from alcohol or drugs was significantly associated with substance abuse. Moreover, having sex while high was significantly related to both risky sex and a history of sexually transmitted disease. Conclusions: Having sex while high may be an important behavior to address to prevent STDs in the DUI population. Assessing relationships between substance abuse and risky sexual behavior poses a challenge to researchers because any estimates about this association may be dependent on the measure of sexual behavior that is used. An integrated intervention approach that addresses both substance abuse prevention and safe sexual practice appears crucial and effective for educating 'risk takers' such as DUI offenders. However, these data caution that for those who are dependent upon alcohol and/or other drugs, education solely emphasizing risk reduction procedures is likely to be inefficient until their chemical dependency is addressed.