Young people are vulnerable to disordered gambling in Chinese societies, such as Macao. This study aimed to assess the extent to which psychological factors (i.e., self-esteem, negative attitudes, subjective norms, and refusal self-efficacy) are associated with disordered gambling relative to two different youth populations. We recruited 809 high school students and 427 undergraduate students in a survey with anonymous, structured questionnaires. As expected, student gamblers reported significantly fewer negative attitudes, more positive subjective norms, and lower refusal self-efficacy than nongamblers. The undergraduate sample reported more positive subjective norms but higher refusal self-efficacy and self-esteem than the high school sample. Refusal self-efficacy was a negative correlate of disordered gambling symptoms in both samples, after gender was controlled for. Moreover, the indirect protective effect of self-esteem on disordered gambling via increasing refusal self-efficacy was also found. The findings suggest that global self-esteem and gambling refusal self-efficacy should be particularly emphasized in preventive interventions for disordered gambling among young gamblers.