Background: The COVID-19 pandemic has led to various psychological consequences. Its sudden emergence has caused widespread confusion, disrupted people's daily lives, and inflicted severe psychological trauma. Objectives: This study seeks to explore the effectiveness of emotional cognitive training in reducing stress and promoting post-traumatic growth among COVID-19 patients discharged from Zahedan hospitals in 2021. Methods: This quasi-experimental study involved 70 COVID-19 patients who were discharged from Zahedan hospitals in 2021. The participants were selected using a convenience sampling method and randomly assigned to either the intervention or control group, with each group consisting of 35 patients. The intervention group received seven online sessions of cognitive-emotional training in groups of 4 to 6 people. The patients completed the Post-traumatic Growth Inventory (PTGI) and the post-traumatic stress disorder (PTSD) checklist before and 12 weeks after the cognitive-emotional training. The data were analyzed using SPSS version 22 and statistical tests such as analysis of covariance, chi-square, and independent t-tests. The significance level was considered < 0.05. Results: The independent t-test and analysis of the covariance test revealed that the mean score of post-traumatic stress in the intervention group (32.34 ± 5.75) was significantly lower than that in the control group (57.88 ± 4.28) following the cognitive-emotional training (P = 0.001). Additionally, the mean post-traumatic growth score in the intervention group (69.8 ± 11.73) was significantly higher than that in the control group (48.71 ± 5.08) after the training (P = 0.001). Conclusions: The results suggest that emotional cognitive training has a positive and significant impact on reducing stress and promoting post-traumatic growth among COVID-19 patients. Therefore, incorporating this online training into the standard treatment is recommended to enhance the well-being and welfare of patients with COVID-19 after discharge.