This study was to examine the relationship between athletic identity and the two dimension of sport commitment: enthusiastic commitment and constrained commitment. Approach: The participants were 539 Vietnamese collegiate athletes (females: 129, males: 410). All participants currently play competitive sport at the varsity or intramural level; their mean age was 18.12 years (SD ± 1.15). The results of this study indicated that athletic identity positively affected both enthusiastic commitment and constrained commitment, the former more strongly. This study finds the causal relationships between athletic identity and the two dimensions of sport commitment in Vietnamese collegiate athletes.