Insulin resistance syndrom (IR) is often associated with the syndrome of microvascular angina pectoris (MVAP) or with coronary artery disease (CAD). The authors quantified distribution and washout of 201Tl in heart (C), lungs (L) and liver (H) to evaluate the results 201Tl stress (s) and redistribution SPECT in 50 patients. They compared 2 groups of patients with laboratory verified IR (MVAP and CAD) and control group (CG) of patients with normal coronarography without any symptoms of IR. In Patients with IR and MVAP were found significantly more frequent local perfusion abnormalities then in CG. The index sL/C calculated by ROI analysis is significantly lower in controls, then in CAD. The index sC/H is lower in patients with IR (MVAP significantly) then in CG. The washout of 201Tl in CAD myocardium decreased and in MVAP liver increased. 201thalium scintigraphy is useful for separation of patients with MVAP and local perfusion abnormalities. This findings had probably prognostic value in patients with IR.