This study investigated concern, control, curiosity, and confidence serially mediated the associations between psychological flexibility (PF) at work and career commitment, based on the career construction model of adaptation and gender, age, education level, and tenure differences in career commitment. The white-collar employees (N = 353, 55% female) completed the Career Commitment Scale, Work-Related Acceptance and Action Questionnaire and Career Adaptabilities Scale-Short Form, and a Demographic Information Form. A multiple serial mediation model indicated that PF at work was related to concern, control, curiosity, and confidence, which in turn, contributed to career commitment, serially. The results of one-way ANOVA showed that career commitment differs according to education level, only. These findings suggested implications for theory, research, and practice, responding to the cultural context.