This study presents the frequency of old myocardial infarctions (OMI), and the frequency of unrecognized myocardial infarction (UMI) in elderly people in a forensic material. It was also examined if predisposing factors of UMI could be identified. Of special interest was also to investigate the value of the police's records as a source for medical information in a forensic setting. The study is based upon medico-legal autopsies of persons above the age of 60 at the time of death during the period 1999-2003. The study included 325 cardiovascular deaths. Of these, 166 died from OMI. UMI accounted for 123 of these (74%). Most UMI were located in the interventricular myocardial septum and left anterior wall (>60%), but no significant differences could be found between UMI and recognized MIs (RMI). No obvious reason could be found as to why the UMI remained unrecognized. Police records were inferior to the hospitals records, regarding medical information to the pathologist, with information about cardiac disease in about 60%, and with information about OMI in 11-17%. Hospital records supplying information about OMI were found in half the cases. It is concluded that unrecognized myocardial infarction is not uncommon among elderly persons, and with a high risk of sudden death. More emphasis should be put in recognizing OMI in ECGs to attempt to reduce the risk of sudden cardiac death.