The Coach-Athlete Relationship Questionnaire was developed to effectively measure affective, cognitive, and behavioral aspects, represented by the interpersonal constructs of closeness, commitment, and complementarity, of the quality of the relationship within the context of sport coaching. The current study sought to determine the internal reliability and factorial validity of the long (the 29-item Long Version Coach-Athlete Relationship Questionnaire) and short (11-item Coach-Athlete Relationship Questionnaire and 13-item Greek Coach-Athlete Relationship Questionnaire) versions of the Coach-Athlete Relationship Questionnaire with a sample of 800 Chinese coaches and athletes. Results supported the internal reliability across all Coach-Athlete Relationship Questionnaire versions examined, while confirmatory factor analyses (CFA) only supported the factorial validity of the three-factor first-order model of the 11-item Coach-Athlete Relationship Questionnaire. The results are discussed in terms of their implications for theory, research, and practice.