Gambling and alcohol problems commonly co-occur during emerging adulthood. Co-occurring problems may relates to personality factors, physical health, mental health and gambling belief systems. In a large sample of colleges students (N = 513), we examined alcohol, gambling and co-occurring problem groups relative to a group without alcohol or gambling problems from large sample of college students. Group differences were found on Constraint and Negative Emotionality (ps ≤ .05). All three groups had a higher score on gamblers’ beliefs of illusion of control compared to the group with no problems (all ps < .05). Those with co-occurring problems had a higher score on illusion of control beliefs than those with alcohol problems only. For luck/perseverance gambling beliefs, those with co-occurring problems had higher levels than other groups on these beliefs. The group with alcohol problems and significantly poorer mental health outcomes than those without alcohol or gambling problems. Individuals with gambling problems or alcohol problems only had significantly poorer self-rated overall physical health (p < .01). Differences were found between groups (alcohol, gambling, alcohol + gambling and neither) on self-rated energy and fatigue as well as pain (ps < .05). Gambling and alcohol problems may relate to emotional and health problems, and personality and belief systems may be related to the co-occurrence of gambling and alcohol problems.