The study reveals preliminary results of a bilateral project involving the Institute of Forensic Medicine, University of Copenhagen (Denmark) and the Institute of Legal Medicine, University of Granada (Spain). Morphological findings were compared to the results of thanatochemical analyses of pericardial fluid and myocardium in the same cases of sudden death of cardiac origin. Fifty cases were included, and the results of the macroscopic, histochemical, histological and cytological examinations revealed that the NBT test and microscopy are valuable methods in diagnosing infarctions, while cytological examination of pericardial fluid seems to be of no value.