Objectives: The aim of this study was to investigate the prevalence of hazardous drinking (HD) and its association with sociodemographic factors, smoking, social anxiety, self-esteem, and ego-resiliency in medical students. Methods: A total of 408 medical students were included in this study. Data were collected by self-administered questionnaire, and HD was assessed by Alcohol Use Disorder Identification Test (AUDIT). The HD and non-HD group were defined using the AUDIT score 10 for male and 6 for female as a cut-off, respectively. Multiple logistic regression analyses were carried out to examine the impact of sociodemographic factors, smoking, social anxiety, self-esteem, and ego-resiliency on HD. Results: A total of 192 participants (47.1%) were identified as having HD. Frequency of smoking and the severity of social anxiety were significantly higher in HD group than non-HD group. Meanwhile, the levels of self-esteem and egoresiliency were significantly lower than HD group than non-HD group. In multiple logistic regression, smoking was associated with a higher risk of HD, whereas ego-resiliency and age were associated with a lower risk of HD. Compared to the high level of subjective socioeconomic status, both middle and low level were associated with a lower risk of HD. Conclusions: HD among medical students was quite common and associated with smoking, ego-resiliency, age, and level of subjective socioeconomic status. Strong efforts to improve smoking cessation and ego-resiliency, as well as education for HD in medical schools, is needed to reduce the harmful effects of alcohol.