Background: In developed countries 50% - 75% of deaths from cardiovascular-diseases occurs out-of-hospital. In Nigeria where patronage of orthodox health facilities is low, the impact of cardiovascular-related diseases on out-of-hospital mortality has been sparsely studied. Objectives: To determine the prevalence and pattern of cardiovascular-related causes of out-of-hospital deaths in Lagos, Nigeria. Methods: A 5-year retrospective review of all autopsied medical decedents brought-in-dead (BID) to a Nigerian tertiary health facility to identify cardiovascular-related causes of death. Results: A total of 90 cardiovascular-related deaths out of 176 medical BID cases were identified, giving a prevalence of 51.1%. Mean age was 65.2 ± 15.6 years. Male: Female ratio was 1.4: 1, the females were older (68.29 ± 14.89) vs (61.63 ± 15.55) years. Age group > 60 years accounted for 63.3% of deaths. Commonest primary diseases were hypertensive heart disease (48.9%) and cerebrovascular accident (24.4%). Myocardial infarction occurred in 8.9%. Heart failure, cerebral dysfunction and unspecified circulatory collapse were the causes of death in 54.4%, 23.3% and 14.4% respectively. Conclusion: Cardiovascular-related diseases are major contributors to out-of-hospital medical deaths occurring chiefly in those >60 years. Hypertensive heart disease and heart failure are the greatest contributors to this cardiovascular–related disease mortality.