This research examined 1) the prevalence of substance use behaviors in college students, 2) gender and academic level as moderators of the associations between mental health problems and substance use, and 3) mental health service use among those with co-occurring frequent binge drinking and mental health problems. As part of the Healthy Minds Study, a probability sample of 2843 college students completed an Internet survey on mental health problems, substance use behaviors, and utilization of mental health care. Response propensity weights were used to adjust for differences between respondents and non-respondents. Major depression, panic disorder, and generalized anxiety disorder were positively associated with cigarette smoking. Frequent binge drinking was negatively associated with major depression and positively associated with generalized anxiety disorder, and these associations were significantly stronger for males than females. Among students with co-occurring frequent binge drinking and mental health problems, 67% perceived a need for mental health services but only 38% received services in the previous year. There may be substantial unmet needs for treatment of mental health problems and substance use among college students.