The development of evidence-based guidelines is an interdisciplinary process in which methodologists play an important role. In addition to creating new or assessing existing systematic reviews as a basis for evidence-based decision making, methodologists can support the entire development process. Due to the increasing complexity of methods and the information overload of available publications, cooperation between the involved experts (especially clinicians and methodologists, but also patient representatives) is essential in order to develop reliable, acceptable and practical guidelines. This article looks at eight key points of the guideline development process (transparency, conflicts of interest, composition of guideline development group, establishing evidence foundation, development and formulation of recommendations, external review and updating) from the perspective of methodologists, and highlights problems, challenges and solution approaches. The earliest possible involvement of methodologists, a clear and a - for non-methodologists - understandable presentation of the best available evidence, the integration of methodologists in the creation and formulation of recommendations (systematic, evidence-based decision-making process) and cooperation between the participating experts are essential to improve the development process of evidence-based guidelines.