OBJECTIVE The purpose of this study was to examine the association between Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), alcohol-use disorders (AUDs) and nonmedical use of prescription drugs (NMPD) among U.S. college students. A secondary aim of this study was to identify individual-level and college-level characteristics associated with the co-occurrence of AUDs and NMPD. METHODS Data were collected from self-administered mail surveys, sent to a random sample of approximately 14,000 college students from a nationally representative sample of 119 U.S. colleges and universities. RESULTS Among U.S. college students, those with AUDs represented approximately 75% of nonmedical users of prescription drugs. Multivariate logistic regression analyses indicated that college students with past-year DSM-IV alcohol abuse only (adjusted odds ratio [AOR]=4.46, 95% confidence interval [CI]=3.59-5.55) and students with past-year DSM-IV alcohol dependence (AOR=9.17, 95% CI=7.05-11.93) had significantly increased odds of NMPD in the past year compared with students without AUDs. The co-occurrence of AUDs and NMPD was more likely among college students who were male, white, earned lower grade point averages, and attended co-ed colleges and institutions located in Southern or Northeastern U.S. regions. CONCLUSIONS The findings provide evidence that NMPD is more prevalent among those college students with AUDs, especially individuals with past-year DSM-IV alcohol dependence. The assessment and treatment of AUDs among college students should account for other forms of drug use such as NMPD.