The double tracer (99mTc-MIBI and 99mTc-Amiscan) scintigraphy is an useful technique to imagine cardiac injury due to CO intoxication. Accumulation (retention) of 99mTc-MIBI is dependent on blood flow and cellular and mitochondrial electrical potential of myocytes. The lower tracer accumulation is seen not only in necrotic heart tissue regions, but also in ischemic area of worse metabolic rate and perfusion. 99mTc-Amiscan contrary to 99mTc-MIBI, is accumulated only in regions of early necrosis so it can be can distinguished from transitory ischemia. Mechanisms of cardiac injury due to CO toxicity is different than due to coronary occlusion and the process of the heart damage is usually much longer. Results of control stress-rest 99mTcMIBI scintigraphy, performed after 6 months from CO exposure in relation to the clinical state on admission and results of 99mTc-MIBI and 99mTc-Amiscans scans obtained in acute phase of poisoning are presented in the study. Initial 99mTc-MIBI SPET examination had confirmed transitory myocardial ischemia of different degree in all the examined patients. The mutual dependence between degree of scintigraphic changes and blood lactate level and CK activity was found. 99mTc-Amiscan scintigraphy demonstrated areas of necrosis in myocardium of some patients; they had statistically higher COHb and blood lactate concentration compared to the rest. A control stress-rest 99mTc-MIBI SPET performed 6 months after CO intoxication, confirmed a late consequences of metabolic abnormalities and a necessity of cardiovascular system follow-up controlling.