Opioid analgesic dependence (OAD) is recognised as a public health concern in several countries: until now research has focused mainly on the USA, where opioid analgesic overdose has been described as an “epidemic”, but evidence suggests it is becoming an increasingly severe problem in Europe. Despite growing recognition of OAD as a major health issue, there is little in the way of scientific literature or guidelines available to aid clinicians, and often the fields of pain and addiction medicine work in isolation without the benefit of each other’s expertise. The OPEN consensus project represents the first collaboration of European experts in pain and addiction medicine to share their knowledge, suggest ways the specialties can work more closely together to care for patients, and strengthen communication between the disciplines. Starting in 2014 this pioneering consensus project is bringing together pain and addiction medicine specialists for the first time to explore the diagnosis and treatment of patients who develop addiction to opioid painkillers. The Opioid Analgesic Dependence Education Nexus (OPEN) gathered 35 leading international figures in pain and addiction medicine to discuss the emerging problem of opioid analgesic dependence (OAD) and reach agreement on the best way to manage this complex group of patients. At a meeting in June 2015, the OPEN Expert Panel developed a set of consensus statements based on their clinical experience and opinions on OAD, which were reviewed and refined by the other OPEN members. Areas of conflicting opinion or disagreement with the consensus were synthesised into a second set of statements, which were discussed and amended by the whole group at a follow-up meeting in November. The product of this process is a “consensus and controversies” publication, currently being prepared for submission to a medical journal later in 2016. The publication uniquely presents not only the areas of high agreement between pain and addiction medicine, but also the areas of greatest controversy. OPEN members have pledged to using their positions as key figures in national and international societies to help circulate the publication throughout Europe, so that healthcare professionals treating patients with OAD can benefit from the clinical expertise of the OPEN group.