Objective To calculate standardised mortality ratios (SMRs) for a cohort of homeless people in the Dublin region over a 5-year period and to examine leading causes of death.

Setting Homeless services reporting deaths from homeless persons in their care across the Dublin Homeless Region.

Methods Death data among people who experience homelessness was acquired from the Dublin Region Homeless Executive (2011–2015) and validated from both death certificates and records from the Dublin Coroner’s Office.

Participants Two hundred and nine deaths were recorded; of these 201 were verified (n=156 males, 77.6%). Deaths that could not be verified by certificate or coroners record were excluded from the study.

Results SMRs were 3–10 times higher in homeless men and 6–10 times higher in homeless women compared with the general population. Drug and alcohol-related deaths were the leading cause of death, accounting for 38.4% of deaths in homeless individuals. These were followed by circulatory (20%) and respiratory causes (13%).

Conclusion Mortality rates among homeless persons are exceptionally high. Services and programmes, particularly housing and those targeting overdose and alcoholism, are urgently needed to prevent premature mortality in this vulnerable population