Introduction: Apical ballooning syndrome (ABS) is a disorder in heart patients that psychological backgrounds play a role in its onset. The aim of this study was to evaluate the effect of stress inoculation training (SIT) on stress and the psychological capital in patients with apical ballooning syndrome to improve the quality of life of these patients. Materials and Methods: This study was experimental which conducted on 20 patients with apical ballooning syndrome in Sanandaj, Iran. The patients were selected using simple sampling and randomly divided in two intervention and control groups. For intervention group stress inoculation training was held in eight weeks. The level of stress and psychological capital were evaluated before intervention, one week and one month after intervention in both intervention and control groups. Data were analyzed using SPSS Ver. 20. Results: The mean age of patients in two groups was 34.21 ± 3.60 years. In terms of gender, age, and education there was no significant difference between the two groups statistically (p> 0.05). The results also showed that in terms of the level of stress and psychological capital there was significant difference between the two groups statistically (p=0.000). Conclusion: Stress inoculation training significantly reduced stress and increased psychological capital consequently it could reduce ABS.