Purpose: We aimed to evaluate the effects of preoperative pulmonary hypertension (PH) on early and long term results in patients undergoing coronary bypass surgery and the effects of coronary bypass surgery on PH.Methods: Among 2325 patients who underwent elective isolated coronary artery bypass surgery between March 2003 and March 2012, 287 patients with high preoperative pulmonary arterial pressure (PAP) ≥30 mmHg were examined. Patients’ data were obtained by retrospective examination of our clinic’s database. 69 patients who had complete parameters included in the study.Results: There was no increase in the New York Heart Association (NYHA) functional classification 84% of cases. Preoperative and postoperative values of the mean ejection fraction and mean PAP of patients was respectively 45.28 ± 9.67 (25–65), 46.03 ±12.4 (20–65) (p = 0.447), 36.67 ± 6.81 (30–60) mmHg, 37.81 ± 10.07 (20–70) mmHg (p = 0.378). The late mortality of cases was 5.79%. In our study, during 33.9 ± 17 (9–100) months follow up period, life expectancy was calculated as 94.7 months.Conclusion: Preoperative evaluation of these patients for appropriate medical treatment at peroperative and postoperative period, coronary bypass can be performed with low morbidity and mortality rates. In the late period after surgical revascularization PH showed no significant change and had no adverse effect on quality of life.