Although it is possible to find a number of comparative studies in the world literature discussing the results of coronary artery bypass surgery (CABG) with and without cardiopulmonary bypass (CPB), until now such analysis has not been made in Bosnia and Herzegovina. The main aim of this scientific work was to compare morbidity and mortality, need for blood transfusions, length of stay in the intensive care unit and total length of hospitalisation in two groups of patients operated with these methods. One hundred and four patients with coronary artery disease operated in Cardiovascular Clinic Tuzla, from September, 1998 to September 2002 divided in two groups, were included in this study. There were 52 patients in the first group operated with CPB and 52 patients in the second group operated without CPB. The groups were matched for gender, age, ejection fraction and preoperative risk factors. The incidence of postoperative complications was lower in patients operated without CPB (5.77% vs. 21.15%). The mortality rate was reduced in patients operated without CPB (0.00% vs. 5.76%). There were reduced need for transfusion in patients operated without CPB (0.28 vs. 1.11 units of blood). The average time spent on respirators was shorter in patients operated without CPB (1.50 vs. 4.76 hours). The average time of total hospitalisation was also shorter in patients operated withouth CPB (6.53 vs. 8.13 days). In conclusion CABG without CPB has many advantages compared to the conventional method. Mortality and morbidity are reduced and there is less need for transfusion. The time spent on mechanical ventilation is reduced and less time is spent in intensive care and the total hospitalisation time is also less.