Abstract Background Sexually transmitted infections (STIs) present a continuing challenge to the efforts to prevent disease in the military. Since the degree of high-risk sexual behavior is a primary determinant for acquiring STIs, the identification of personality traits or situations associated with such behavior is of special interest. Methods Data for this study were obtained from the 1998 Department of Defense Survey of Health Related Behaviors Among Military Personnel. The survey instrument was a self-administered questionnaire that was conducted using a stratified, two-stage, two-phase probability design to obtain representative samples of U.S. active duty personnel worldwide. Results More frequent episodes of alcohol intoxication were associated in a dose-dependent manner with an increased risk of having more sexual partners in the previous 12 months. Men and women who experienced intoxication more than 3 days per week were, respectively, 4.55 and 6.18 times more likely to have more than one sexual partner in the previous year. Conclusions This study is based on retrospective self-report and may be subject to recall bias as well as information bias due to the sensitive nature of the subject matter. However, the results are compatible with a personality-based hypothesis, in which individuals with certain sensation-seeking tendencies may incur an increased risk for sexually transmitted infections.