Introduction: Psychiatric issues, particularly depression and anxiety, have been observed in the proportions of patients undergoing cardiovascular surgery.Such findings provide a window of opportunity for integrating intervention, targeting psychological components into post-Coronary Artery Bypass Graft (CABG) patient management to provide effective care. The Buteyko Breathing Technique (BBT), which is named after its inventor Konstantin Pavlovich Buteyko, is one of the numerous breathing techniques that aims to regulate breathing. By alternating between periods of controlled breathing reduction and breath holding. Aim: To explore the effect of BBT as a psychological rehabilitation technique on anxiety, depression, and self-efficacy in postCABG subjects having anxiety and depression. Materials and Methods: This randomised clinical trial was performed at Cardiovascular and Thoracic Surgery Unit, Acharya Vinobha Bhave Rural Hospital, Sawangi, Wardha, Maharashtra, India, from June 2021 to May 2022. Total 44 post CABG patients who all screened positive for anxiety and depression by General Anxiety Disorder-7 (GAD-7) questionnaire and Patient Health Questionnaire-9 (PHQ-9) were enrolled. They were randomly assigned using computed generated block randomisation. They were allocated using the Sequentially Numbered Opaque Sealed Envelope (SNOSE) method to group A Conventional group (n=22) and group B Experimental group (n=22). Both groups competed the in-hospital phase 1 cardiac rehabilitation as per American Association of Cardiovascular and Pulmonary Rehab (AACVPR) guidelines, whereas group B received additional BBT for psychosocial rehabilitation for 2 weeks post surgery. The evaluations were performed using the GAD-7 questionnaire, PHQ-9, General Self-Efficiency Scale (GSS), Breath Holding Test (BHT), and Borg Rate of Perceived Exertion Scale (RPE), at baseline on Post Operative Day (POD)1 and at their last rehabilitation session. Patients in both groups were given self management and education hand-outs at the time of discharge. Statistical Package for Social Sciences (SPSS) version 27.0 was used for statistical analysis. Results: The mean age of patients in A-group was 59.72±7.84 years and in B-group 60.81±7.42 years, respectively. The age, gender, height, weight, and BMI of the patients were similar between the groups. On intra group comparison ,there was statistically significant difference observed for GAD-7, PHQ-9, GSS, BHT, and RPE in group A and group B following the intervention, but the change was more pronounced in group B. The results for the inter group comparison showed a significant difference in group B on Anxiety, Depression, self-efficacy, BHT, and RPE as compared to the group A, i.e. group B showed a larger improvement in outcome measure scores than group A. Conclusion: The present study demonstrated that On intra group weeks of BBT along with phase 1 cardiac rehabilitation in post CABG patients brings favourable changes in levels of anxiety, depression and self-efficacy.