The purpose of this study was to examine the relationship between control beliefs about stress and post‐traumatic growth among Chinese nurses during the COVID‐19 pandemic and to examine the mediating role of basic psychological needs satisfaction and optimism in this relationship. A total of 692 Chinese nurses participated in this online study, who completed the Beliefs about Stress Scale, Post‐Traumatic Growth Inventory, Positive Psychological Capital Questionnaire, Basic Psychological Needs Satisfaction Scale and demographic variables between September and October 2020. Results indicate that 48.8% (N = 388) of nurses reported significant post‐traumatic growth related to the COVID‐19 pandemic. Moreover, control beliefs about stress were positively related to post‐traumatic growth (r = 0.38, p < 0.001), basic psychological needs satisfaction (r = 0.44, p < 0.001) and optimism (r = 0.47, p < 0.001). In addition, basic psychological needs satisfaction and optimism were both independent and serial mediators of the relationship between control beliefs about stress and post‐traumatic growth. Nurses and hospital administrators should focus on increasing nurses' control beliefs about stress and thereby enhancing their post‐traumatic growth after experiencing events such as the COVID‐19 pandemic. To support this process, programs should be designed to meet nurses' basic psychological needs and increase their optimism.