Benzodiazepines are a widely prescribed group of medicines with a range of clinical uses, including the treatment of anxiety and insomnia and the management of alcohol withdrawal. For a number of reasons this group of medicines are often misused by high-risk opioid users and are associated with morbidity and mortality among this group. This ‘Perspective on drugs’ considers the significance of this problem and its impact for the health and drug treatment of opioid users.