Objective: Poisoning with carbon monoxide (CO) due to flash gas heater or stove being an important health problem in our region, causes significant pathologies in the body as well as death by decreasing oxygen-carrying capacity of blood. This study was planned to assess whether or not myocardial damage occurs in patients with CO poisoning. Methods: Forty consecutive adult patients with CO poisoning (30 females and 10 males) were included in this study. The mean age of the patients was 28.5±9.9 years (range: 15-56). The demographic characteristics, vital signs, the origin of CO gas, risk factors for coronary artery disease (CAD) and smoking habit of the patients were recorded. The evaluation of Glasgow Coma Scale score, electrocardiogram (ECG), peripheral arterial blood gases, complete blood count, creatine kinase (CK), creatine kinase-myocardial band (CKMB), troponin-T measurements were performed in all cases. Additionally, myocardial perfusion SPECT was performed in three cases with carboxyhemoglobin (COHb) levels over 50%. Results: Sinus tachycardia, was observed in 9 cases. Ventricular bigeminy was seen in a case with troponin-T positive test. Six of 40 cases (15%) had significantly increased CK and CK-MB levels with normal troponin-T measurements. High troponin-T levels (0.13 ng/ml) were detected only in 1 case with COHb level of 61.3%. Myocardial SPECT was performed in 3 cases with COHb levels higher than 50% and no images compatible with defects could be identified. Conclusion: The results suggested that significant myocardial damage and life-threatening cardiac hemodynamic changes do not develop in CO-poisoned patients with COHb level below 60 % and without any known underlying CAD. It is not necessary to routinely measure CK, CK-MB and troponin-T, and perform myocardial perfusion SPECT in acute CO poisoning cases without any ECG abnormality, ischemic cardiac symptoms or known CAD.