Calls for scaling up successfully tested health service innovations have multiplied over the past several years. Many acknowledge that pilot or experimental projects are of limited value unless they have larger policy and programme impact. Moreover, there is increasing recognition that prove innovations cannot simply be handed over with the expectation that they will automatically become part of routine programme implementation. While there has been progress, there is still little practical guidance on how to proceed with scaling up. This document, Practical guidance for scaling up health service innovations, can begin to fill this gap. One of the important contributions of the document is that it both identifies general principles and makes very specific, concrete suggestions. Guidance is organized around a framework that highlights the interrelationships among the central elements and strategic choices involved in scaling up.