Background: Type D personality, a newly specified personality type defined as the interaction of high levels of negative affectivity and social inhibition, is associated with poor health outcomes. Few interventional studies have been performed to improve health outcomes in this subpopulation. Purpose: This study was developed to examine the effects of an educational intervention on psychological health, health-promoting behaviors, and quality of life in coronary heart disease (CHD) patients with type D personality in China. Methods: A randomized controlled trial was adopted. One hundred twenty-eight patients with CHD and type D personality were randomly assigned. The intervention group received the 12-week educational intervention in addition to usual care, whereas the control group received usual care only. Data on anxiety and depression, health-promoting behaviors, and quality of lifewere collected at baseline and at 1 and 3months after enrollment. After controlling for the covariates, the generalized estimating equation model was used to examine the intervention effects. Results: Themean age of the participantswas 61.02 years, and more than 70%were male. Results of the generalized estimating equation analysis showed significantly greater improvements in anxiety, depression, and health-promoting behaviors in the intervention group than in the control group. In addition, quality of life, the domains of angina limitation, angina stability, and treatment satisfaction were found to have improved more significantly in the intervention group than the control group, whereas the posttest changes in angina frequency and disease perception were found to be similar in both groups. Conclusions/Implications for Practice: The educational intervention was shown to be effective in improving psychological health, health-promoting behaviors, and certain domains of quality of life in patients with CHD and type D personality. Nurses should identify patients with this personality type and provide tailored care to improve their health outcomes in clinical practice.