Patients awaiting cardiac surgery generally experience physical and psychological stress. Excessive fear or distress before surgery is associated with slower and more complicated post-operative recovery. Although effects of psychoeducation in enhancing post- surgical outcomes among cardiac surgery patients have been studied abroad, its efficacy has never been studied among patients undergoing cardiac surgery in Bangladesh. Moreover, no psychoeducation material has ever been developed to help cardiac surgery patients in Bangladesh. The purpose of the present study was to test the efficacy of psychoeducation intervention in helping patients undergoing cardiac surgery. Psychoeducation material was developed and then its ability to reduce anxiety, depression, surgical complications, and length of hospital stay; and to enhance recovery, satisfaction with care was tested. A two phased mixed-method design was adopted to achieve the objective of the study. Rigorous qualitative exploratory approach was used in the development of psychoeducation material in the first phase. It targeted exploration of patients’ emotions, thoughts and psychosocial needs related to cardiac surgery and these insights were used in the development of content for psychoeducation. The first phase used, in-depth interview with patients and professionals, observation, literature review, panel discussions at different parts of the process. The second phase involved quantitative experimental design where efficacy of the psychoeducation intervention was tested using comparative outcome study design. Patients were assigned to two groups where one group received psychoeducation (25) and the other group received breathing relaxation (25). The study questionnaire included custom built miniscule tools and validated psychometric instruments to measure different bio-psycho- social outcome variables. Three levels of data analysis were done namely, within group pre-post score difference (e.g., baseline, post intervention, post surgery, follow up), between group post score difference (i.e., surgery aspects) and between group gain score difference (gain = post - pre). In these analyses, significant results were found sporadically on different outcome variables for both psychoeducation and breathing relaxation group. However, a complete picture of relative impact of psychoeducation and relaxation was found in the comparative gain score analysis of follow-up scores. Results from the analysis of gain score on baseline- follow-up comparison indicated that the psychoeducation group reported significantly better sleep quality (t=2.64, p 0.05), concentration (t=2.52, p 0.05), mood state (t=2.62, p 0.05), self confidence (t=3.43, p 0.01), general interest (t=3.43, p 0.01), medicine compliance (t=2.44, p 0.05), and compliance to health instructions (t=2.28, p 0.05) compared to breathing relaxation group. Psychoeducation group also demonstrated significantly decreased lifestyle impairment (t=3.25, p 0.01) and work impairment (t=3.26, p 0.01) compared to the relaxation group. Among the 19 outcome indicators considered in the baseline-follow-up comparison, nine were found to have significant difference in gain score between psychoeducation and breathing relaxation group. In all these nine outcome indicators, psychoeducation group outperformed breathing relaxation group. These findings suggest that impacts of psychoeducation are long standing and its effect can be tracked in follow-up phase among cardiac surgery patients.