This study aimed to examine whether and how organizational factors (i.e., procedural justice) are associated with psychological flourishing, an optimal mental state. Path analysis was conducted among 195 Chinese mental health professionals (females = 69%; Mean age = 30 years) in Macao, and results showed that emotional exhaustion partially mediated the positive association between procedural justice and psychological flourishing, whereas emotion regulation significantly diminished the effects of procedural injustice on emotional exhaustion. Our findings highlight the emotional mechanisms underlying the influence of organizational procedures on employees' wellbeing, and wellness programs for enhancing employees' emotional regulation skills are recommended.