Background: SIDS is a diagnosis of exclusion applied to the death of an infant < 1 year of age after an extensive post-mortem investigation. From 1980 to 2018, a total of 870 infants have been autopsied at the Section of Forensic Pathology, Department of Forensic Medicine, UCPH, covering East Denmark. In the same period, Danish national guidelines for infant care have been revised to avoid infants dying of SIDS. Objective: This study aimed to describe trends in infant autopsies regarding cause and manner of death, gender, age, month of death, sleeping position, and bed-sharing. The trends were compared to the change in national SIDS guidelines during the period of this study. Design: Information from autopsy reports from 1980 to 2018 were collected into 55 categories designed specifically for this study. Data from 7 of these categories were chosen and processed in Excel for basic epidemiological comparison. Results: The trends show that most infants in the study die of natural manner and most predominant causes of death are SIDS, infection, and congenital malformations. A change in national guidelines in 1991 recommending supine- or side sleeping position coincided with a reduction in the overall infant mortality and cases of SIDS. The peak age in the cohort is 90 days, but stratification in decades shows the infants dying younger each decade. Through the study period, the number of infants found dead sleeping in the prone position has declined. Relatively more infants in this cohort have been found dead while bed-sharing, even though the prevalence of these cases has remained largely the same for four decades.