The two most common causes of death in the period 2011–2020 were diseases of the circulatory system (32%) and neoplasms (28.4%). The third and fourth most common causes were diseases of the nervous system (10.5%) and the respiratory system (8.5%), respectively.

Statistics Iceland has published new data on causes of death for the year 2020. The data are based on classification of death certificates of all persons who died during this period with a legal domicile in Iceland.

Leading causes of death 2011–2020
Circulatory system32.0%32.9%31.1%
Nervous system10.5%8.5%12.5%
Respiratory system8.5%7.4%9.6%
External causes6.6%8.3%4.9%
Other causes14.0%13.4%14.6%

Causes of death are dependent on age. For 0–34 years old, the most common cause of death was external, corresponding to 55% of all deaths in the age group. Gender differences are substantial as 61% of men die of external causes versus 42% of women. The most common cause of death for 35–64 years old is neoplasms or 44%. There is a difference between the sexes as more women (57%) die of neoplasms than men (35%) in the age group. However, it should be noted that deaths are relatively fewer for people under the age of 65, or 17% of all deaths in the period 2011–2020. For 65–79 years old, neoplasms are still the most common cause (43%) and circulatory diseases second most common (26%) while the order of other causes of deaths is the same as for other age groups. The proportion changes when it comes to 80 years old and older, where circulatory diseases are the most common cause of death or 39% compared with 19% for neoplasms.

Deaths caused by the nervous system increased by 89% from 2001–2020
The totals and percentages of each cause of death depend on the age structure of the population. In order to study development over time as well as a cross-country comparison, statistical offices use standardised death rates (per 100,000 inhabitants of the Eurostat-2013 standard population). The cause of death that increased the most from 2001 to 2020 were due to diseases of the nervous system, increasing from 46 per 100,000 inhabitants in 2001 to 87 in 2020, an increase of 89%. The standardised rates for deaths caused by the circulatory system decreased by 41% (from 422 to 248 per 100,000 inhabitants) from 2001–2020. Similar trends were noted for tumors and respiratory diseases, where the decrease was 22% and 21% respectively over the same period.

Notes: vertical axes display the rates per 100,000 inhabitants, using Eurostat-2013 standard population, right hand side axis for circulatory system and neoplasms; left hand side vertical axis for nervous, respiratory system and external causes.

29 individuals died from COVID-19 and 1 from post COVID-19 condition in 2020
Two new morbidity codes were introduced in 2020, both related to COVID-19; "COVID-19 (Coronavirus disease 2019)" and "Post COVID-19 condition, unspecified". In 2020, 29 individuals died from Covid-19 and one person from post COVID-19 condition.