Anatomo-physiopathological and chronobiological features of 59 diabetic subjects out of 610 non hospitalized individuals observed for sudden death (SD) in an Emergency Room, over an 8-year period, were studied. Mean age and anatomopathological causes of SD were not different between diabetic (DMs) and non-diabetic subjects (NDs). However the frequency of DMs was higher among subjects who died from circulatory failure death (CFD), rather than from arrhythmic death (AD). Diabetics presented a prevalent peak incidence of SD in the afternoon-late evening; whereas in NDs two peaks were present, respectively in the morning and in the afternoon. According to anatomo-physiopathological causes, DMs presented a higher incidence of acute myocardial infarction (AMI) and CFD between 21:01 and 24:00, whereas in NDs the prevalent peak of AMI was observed in the early afternoon (13:01 to 16:00). Moreover, in DMs SD from acute myocardial failure prevalently occurred in the early afternoon (13:01 to 16:00), whereas in NDs it was uniformly distributed throughout the day. The present study seems to indicate that different anatomo-physiopathological causes of SD may present specific temporal patterns in diabetics.