The effect of HTK solution for myocardial protection is shown in experimental and clinical studies at which cases with long ischemic time and with high dosage. In our study we compared the effectiveness of low dosage HTK and cold crystalloid cardioplegia in terms of myocardial protection in isolated coronary bypass with a short period of ischemia. Each group contains 21 coronary artery disease patients. Cardioplegic solutions were administrated with antegrad way in same amount (10-15 ml/kg) in one shot. This dosage of HTK is lower then mentioned in literature. Malondialdehyde, lactate, creatin kinase, creatin kinase-MB, and troponin-I levels were controlled. Aortic clamping time in HTK group 33.9±8.2 minutes, 36.2±11.3 minutes in crystalloid cardioplegia group (p>0.05). Level of creatin kinase and malondialdehyde were lower in HTK group at 24th hour and second minute respectively. Lactate level was lower in crystalloid cardioplegia group at second minute in serum sample of coronary sinus, but there were not statistically difference of ischemic serum markers in both groups. Only intervals between aortic clamping and cardiac arrest were meaningful statistically (HTK 63.3±14.7 seconds and crystalloid cardioplegia 53.6±15.6 seconds, p=0.044). Our study shows that usage of low dosage HTK in short clamping time operations is succesfull for myocardial protection as crystalloid cardioplegia. Longer time for fibrillation can be explained with low level of potassium in HTK solution. But this length did not cause a biochemical or clinical difference and this might be the result of ingredients in HTK.