Primary Percutaneous Transluminal Coronary Angioplasty (PTCA) is increasingly common method of treatment patients with acute myocardial infarction. The aim of the study was to assess the left ventricular function in patients with myocardial infarction subjected to thrombolysis or primary PTCA. Gated Single Photon Emission Computed Tomography was performed in 40 patients 6 months after myocardial infarction treated either with thrombolysis or primary PTCA. Left ventricular ejection fraction (LVEF), left ventricular enddiastolic (LVED) and systolic (LVES) volumes were analysed both at rest and after stress. Six months after myocardial infarction LVEF was significantly greater and LVED, LVES volumes smaller in patients treated with primary PTCA in comparison to patients treated with thrombolysis. The above observation suggests that patients subjected to primary PTCA might have better functional outcome in comparison to matched patients treated with thrombolysis after 6 months post myocardial infarction.