Background: This study aimed to assess the impact of telephone counseling on quality of life in patients with coronary artery bypass graft. Methods: A quasi-experimental study was conducted with 71 discharged patients after coronary artery bypass graft surgery at Ekbatan Edcuational hospital in Hamadan, Iran, in 2014. The patients were randomly allocated into intervention (n = 36) and control group (n = 35). The intervention group received education and counseling about therapeutic plan via telephone after discharge. Patients in the control group received only routines. All patients completed the quality of life questionnaire before and after the intervention period of five weeks. Results: There was no significant difference between intervention and control group about quality of life before intervention (p = 0.696). However, there was significant and positive deference between the two groups in favor of the telephone counseling after the intervention (P = 0.01) and control group (P = 0.04). Quality of life in the intervention group was significantly better compared to control group (P = 0.01). Conclusions: Telephone counseling could be a cost-effective patient counseling plan for therapeutic adherence after coronary artery bypass surgery in order to improve the patients' quality of life. Practice implications: Telephone counseling is feasible to implement and well accepted for patient counseling for many diseases. (C) 2017 Elsevier B.V. All rights reserved.