This study involved 320 cancer patients from four Northern European countries. Patients with breakthrough pain were questioned about the characteristics of their pain, the current management of their pain, and the acceptability/utility of alternative routes of administration. The median number of episodes was 3/day. Forty-four percent patients reported incident-type pain, 39% spontaneous-type pain, and 17% a combination of these pains. The median duration was 60 min, and the median time to peak intensity was 15 min. Three percent patients reported "mild" pain, 37% "moderate" pain, and 60% "severe" pain. Ninety percent patients stated that the pain interfered with their daily activities. All patients were using opioids as rescue medication (mainly oral morphine/oxycodone), whilst 28% patients were using non-opioids, and 50% patients were using non-pharmacological interventions. Only 55% patients took rescue medication every time they experienced breakthrough pain. Sixty-five percent patients would definitely consider using an oral transmucosal product; patients from Denmark were less likely to answer positively, and a positive response was associated with previous use of the route for breakthrough pain. Seventy-three percent patients reported regular oral problems. Forty-two percent patients would definitely consider using an intranasal product, with 26% patients stating they would definitely not use such a preparation; patients from Denmark and Sweden were less likely to answer positively, and a positive response was associated with male gender, and previous use of the route. Forty-four percent patients reported regular nasal problems. Sixty percent patients would definitely consider using a subcutaneous product, and 44% patients would definitely consider using an intrapulmonary product. Copyright © 2010 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.