The purpose of the present study was to analyze the effects of transmyocardial laser revascularization (TMLR) on myocardial perfusion. The value of <sup>99m</sup>Tc-MIBI scintigraphy in the detection of changes in perfusion of the lased and nonlased segments was assessed as well. In 15 patients before TMLR and then 3 and 6 months afterwards, MIBI scintigraphy and a stress test were carried out. At the beginning of the study, all patients were classified as having angina pectoris class III or IV (according to the criteria of the Canadian Cardiac Society); their ejection fraction was >30%. The parameters of the stress test increased significantly in 70% of the patients. Cardiac scintigraphy revealed improved perfusion of 33.7% of the transient defects within 3 months after TMLR which persisted at 6 months with a clear trend towards further improvement in the lased segments. TMLR has been found to be particularly beneficial in patients in whom other invasive methods of treatment cannot be applied.