Background: An overview of reviews summarizes multiple intervention reviews addressing the effect of two or more interventions for a single health problem. We will conduct several overviews concerning the evidence for the effect of physiotherapy interventions on different chronic diseases commissioned by a Dutch policy maker. We were confronted with some practical and methodological issues when conducting our first overview addressing the effect of physiotherapy on fibromyalgia syndrome. Objectives: To describe the lessons learned from the challenges that we encountered while conducting overviews of reviews and to provide suggestions for improvement. Methods: The Cochrane Database of Systematic Reviews, MEDLINE, EMBASE and PEDRO were searched to find Cochrane and non-Cochrane reviews. We used the methods for conducting an overview of reviews as described in Chapter 22 of the Cochrane Handbook. The AMSTAR checklist was used to assess the quality of the included reviews, the algorithm of Jadad to choose between reviews with the same topic and GRADE to assess quality of evidence. Results: We included one Cochrane review and seven non-Cochrane reviews. Extracting data took a lot of time and essential data were missing in non-Cochrane reviews. Therefore GRADE could only be applied to one systematic review, the Cochrane review. Conclusion: When including non-Cochrane reviews it is important to only select systematic reviews that encompass essential and detailed information such as quality of included randomized controlled trials, outcome measures and point estimates. GRADE is an essential tool for policy makers to base their decisions on but can only be applied to systematic reviews that provide sufficient information such as Cochrane reviews. Additional issues and solutions for conducting overviews will be presented at the Colloquium.