Background. Coronary artery bypass grafting (CABG) is a major surgical operation where athermanous blockages in a patient’s coronary arteries are bypassed with harvested venous or arterial conduits. Aim of study was to assess patient compliance after coronary artery bypass surgery toward therapeutic regimen. Design: A descriptive exploratory research design was used. Setting: The study was conducted at cardiac outpatient clinic affiliated to Fayoum University Hospital. Subjects: A purposive sample of 134 patients after coronary artery bypass graft surgery at setting mentioned before. Tools: Two tools were used for data collection. Tool (I): A structured interview questionnaire consists of (2) parts. part I: Patient s' demographic characteristics, part II: Medical health history of the patients. Tool (II): Patient's compliance to therapeutic regimen consists of (5) parts. Part (1): Morisky medication compliance scale. Part (2): Diet compliance scale. Part (3): Smoking. Part (4): Follow up compliance: Part (5): Exercise compliance. Results: The study results reported that (54%) from the studied patient had total compliance to therapeutic regimen after coronary artery bypass graft surgery. (79%) of the studied patient had compliance to medication. (70.7%) of the studied patient had low risk for diet (high adherence to healthy diet). (61%) of the studied patient had quit smoking. (56.6%) of the studied patient had compliance to follow up. And (44%) of the studied patient had compliance to exercise. Conclusion: The study concluded that more than half of the studied patient were had adequate compliance to therapeutic regimen. Regarding medication compliance majority of the studied patients had compliance to medication and compliance to healthy diet. In relation to follow up and exercise compliance less than half of studied patient had compliance to them.in the same context regarding smoking cession about two thirds quit smoking (still trying to stop smoking). Recommendations: Designing educational program for patient undergoing (CABG) surgery about the importance of adherence to therapeutic regimen.