OBJECTIVES To evaluate mid-term results and one-year graft patency of less invasive coronary artery bypass grafting through a median sternotomy. METHODS From January 1, 1998, to December 31, 1999, 250 patients had coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) through a median sternotomy. The patient base of 188 men and 62 women averaged 61.7 years, mean ejection fraction (EF) was 55.1%. An average of 2.7 (range 1 to 5) distal anastomoses per patient was achieved. Results are compared with a CPB subgroup of patients operated on through a median sternotomy in the same time (N = 1126). In a random subgroup of 100 patients (50 per group) an angiographic control of graft patency was done. RESULTS A non-CPB group showed lesser occurrence of postoperative acute myocardial infarction (p = 0.038), atrial fibrillation (p = 0.029) and lower incidence of renal (p = 0.033) complications. We observed lower operative mortality (p = 0.019), as well as the occurrence of low cardiac output syndrome (p < 0.001) in the off pump group. The follow-up is 36 +/- 12 months and the number of patients with recurrent angina (5.4%), late AMI (0%) and late death (0.4%) is acceptable. We did not find an inordinate number of vein grafts occlusions (2.2%) and stenoses (7.8%) at anastomotic sites. None of the arterial grafts in both groups were occluded. CONCLUSIONS We detected lower incidence of postoperative complications and decreased operative mortality in a non-CPB group. Angiographic assessment displayed an excellent run-off in both groups of patients. Off-pump coronary bypass grafting is associated with sufficient short-term graft patency and mid-term clinical outcomes.