Currently the term «mechanical dyssynchrony» means a temporal heterogeneity in the activation and contractility of various parts of the heart. The principles of radionuclide methods for cardiac mechanical dyssynchrony determining differ with other visualization techniques. For scintigraphic assessment of dyssynchrony gated myocardial perfusion imaging and gated blood-pool SPECT are used. This review is dedicated to the possibilities of these methods in assessment of cardiac mechanical dyssynchrony in patients with chronic heart failure, coronary artery disease and cardiac arrhythmias. A description of a data acquisition, as well as reference figures of dyssynchrony in normal and pathological conditions are presented. Nowadays the nuclear cardiology methods are promising in the prediction to cardiac resynchronization therapy. In patients with coronary artery diseases, the presence of severe dyssynchrony on post-stress images is a sign of stunning. This symptom could be used for multivessel coronary artery lesion identification. Moreover, the presence of cardiac dyssynchrony could be useful in Wolf-Parkinson-White syndrome, arrhythmogenic right ventricular cardiomyopathy as well as ventricular arrhythmias diagnostic.