According to the World Health Organization, an increased ratio (more than 6%) of CPK-MB to total CPK may indicate the diagnosis of an acute infarction. But false elevation of CPK and CPK-MB levels after noncardiac operation, because of soft tissue damage, may confuse the clinicians in detecting myocardial infarction in early postoperative period. In order to determine the usefulness of CPK-MB to total CPK ratio in detecting myocardial infarction after open and laparoscopic cholecystectomy, we measured the serum levels of these markers in 135 patients, immediately after the operation and for the next five days. Patients were divided into four groups according to type of surgical procedure, as follows: Group I: a right oblique subcostal (Kocher's) incision was performed in 29 patients, Group II: a right paramedian transrectal incision was performed in 52 patients, Group III: a vertical high midline incision was performed in 17 patients, Group IV: laparoscopic cholecystectomy was performed in 37 patients. Although we found increased levels of CPK and CPK-MB after all the types of cholecystectomy, but in any case the CPK-MB exceeded more than 6% of total serum CPK. Furthermore we noticed that the patients who underwent open cholecystectomy with right oblique subcostal incision had the most elevated CPK and CPK-MB levels comparing to the other types of cholecystectomy. In conclusion, tissue damage after elective cholecystectomy is minimal and CPK-MB to total CPK ratio is a secure marker in detection of myocardial infarction during early post-operation period, after cholecystectomy.