Through Structural Equation Modeling, this study aimed to revise and examine the Attitudes–Social Influence–Efficacy Model in explaining the psychosocial process of betel quid use among Southern Taiwan college students. A representative sample of 3741 college students were recruited from 14 colleges through stratified and random cluster sampling, yielding 3162 valid participants. Results showed that the revised ASE model accounted for 26.5% of the variance in betel quid use and had a better model-fit evaluation than the original model. Intention to chew affected the use of betel quid, while both social influence and refusal self-efficacy had a direct impact on intention and use as well as an indirect effect on use through intention. Additionally, both positive and negative outcome expectancies predicted intention and betel quid use via refusal self-efficacy. Our results supported the revised ASE model for explaining the psychosocial processes of betel quid use, suggesting that more attention should be given towards the development of school-based preventive programs on diminishing social influence and promoting refusal self-efficacy in betel quid use.