The radionuclide investigation was performed 1-3 and 24 hours after injection of a radiopharm preparation and included the single photon emission computed tomography of the heart and scintigraphy of the whole body. Inflammation foci were found on the scans as hyperfixation foci of autoleukocytes labeled with 99mTc-HMPAO (hexamethylpropilene aminooxime). Four patients had abscesses with 0.8-1.5 cm diameter in projection of the aortal and mitral valves of the heart, and in 10 patients there were foci of inflammation and suppuration of extracardiac localization (in the area of the operation wound, anterior mediastinum, frontal sinuses, transverse colon, parietal pleura). The data obtained convincingly speak of high sensitivity and specificity of radionuclide diagnostic methods with the help of labeled elements of the whole blood in recognizing latent inflammatory and suppurative processes in cardiosurgical patients at the pre- and postoperative periods.