This is the peer reviewed version of the following article: Powell, R, Ahmad, M, Gilbert, FJ, Brian, D & Johnston, M 2015, 'Improving magnetic resonance imaging (MRI) examinations: Development and evaluation of an intervention to reduce movement in scanners and facilitate scan completion' British Journal of Health Psychology, vol 20, no. 3, pp. 449-465., which has been published in final form at 10.1111/bjhp.12132. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.