Purpose: The overall aim of the project was to update and inform nurses of current best practice based on previously published literature to enable nurses to assess and manage breakthrough cancer pain (BTCP) and thereby to provide optimal management of BTCP. Methods: The EONS started a project in 2010 by recruiting a working group and a multidisciplinary advisory board to develop guidelines with the purpose of helping oncology nurses understand and recognise BTCP. Results: This paper presents and overview of the guideline. Key recommendations include; using an algorithm for assessment of BTCP, individualise treatment interventions, optimization of analgesia and reassessment of outcomes of interventions. Conclusions: By implementing the EONS guidelines nurses will utilise the latest available knowledge in clinical practice and the understanding and management of BTCP will improve assessment and overall management of breakthrough pain in cancer patients. (C) 2013 Elsevier Ltd. All rights reserved.