Background: Deaths from opioids have increased in England and Wales, despite recognition of their harms. Coroners Prevention of Future Death reports (PFDs) provide important insights that may enable safer use and avert harms, yet these reports involving opioids have not been synthesised. We, therefore, aimed to identify opioid-related PFDs and explore concerns expressed by coroners to prevent future deaths. Methods: In this systematic case series, we screened 3897 coronial PFDs dated between 01 July 2013 and 23 February 2022. These were obtained by web scraping the UKs Courts and Tribunals Judiciary website to create an openly available database: https://preventabledeathstracker.net/. PFDs were included when an opioid was implicated in the death. Included PFDs were descriptively analysed, and content analysis was used to assess concerns reported by coroners and responses to such concerns. Findings: Opioids were involved in 219 deaths reported by coroners in PFDs (6% of all PFDs), equating to 4418 years of life lost (mean 32 years/person). Morphine (29%), methadone (23%), and diamorphine (16%) were the most common implicated opioids. Coroners most frequently raised concerns regarding systems and protocols (52%) or safety issues (15%). These concerns were most often addressed to NHS organisations (51%), but response rates were low overall (47%). Interpretation: Opioids could be used more safely and appropriately if coroners' concerns in PFDs were addressed by national organisations such as NHS bodies, government agencies, and policymakers, as well as individual prescribing clinicians.