Previous studies have noted that acute rejection (AR) may lead to loss of cardiomyocytes in transplanted hearts. The aim of this study was twofold; first to assess the degree of apoptotic cells and to compute the proliferation index of cardiomyocytes and mononuclear interstitial infiltrates in cardiac allografts; second to determine whether apoptosis is involved in acute rejection. Total 28 endomyocardial biopsies were included in to the study. Of 28 biopsies, 18 showed AR and remaining 10 biopsies showed nonspecific changes which they were used as a control group. All biopsies were immunostained with Ki-67 and CD68 antibodies. Apoptotic cells were detected and counted in all biopsies by the TUNEL method. Apoptotic cell death of cardiac myocytes and interstitial mononuclear cells were significantly higher in cases with allograft rejection compared to control group (p<0.05). In addition compared to control group AR cases showed higher degree of proliferation index of cardiac myocytes and interstitial cells (p<0.05). Macrophage infiltration was significantly higher in AR cases and macrophage infiltration shows linear association with both apoptosis and proliferation of myocytes and interstitial cells (p<0.001). In conclusion we verified the presence of apoptotic cell death during acute rejection in heart transplants. The apoptotic cell death was significant on interstitial cells but it was slighter in cardiac myocytes and macrophage infiltration has a great influence on apoptotic cell death of myocytes and interstitial cells.