The pericardial adhesions following the first open heart surgery pose a major problem that can increase the morbidity and mortality in cases of reoperation because of the danger of damaging the heart, great vessels or grafts. The purpose of this study was to determine the effect of intrapericardial infusion of 5% dextrose solution and heparin on experimental pericardial adhesions. The 15 white rabbits were divided into three treatment groups of 5 animals each: group 1 [control group], group 2[5% dextrose group] and group 3 [heparin group]. At 4 weeks, all animals were sacrificed and the pericardial adhesions were graded as follows: 1[none], ll[mild], Ill[moderate] and IV[severe]. Histological examination was performed on a subset of each group. The difference of adhesion between control and heparin group was evaluated by Chi-square analysis. The results were as follows: 1. Pericardial adhesions developed in 80% of animals in group 1 and 2. 2. Only 40%> of animals in group 3 had mild to moderate pericardial adhesions. This was significantly different from the control group [P=0.01]. 3. Histological examination showed that the pericardium with adhesion was thickened with fibrosis, while that without adhesion was thin, normal appearance. 4. In group 3, there was no evidence of hemorrhage or hemorrhagic tendency in the pericardium.