 The great CERQALL approach provides guidance on assessing the confidence in findings from systematic reviews of qualitative research. It has been developed to support decision-making processes such as guideline development and policy formulation. Confidence in the evidence from qualitative evidence synthesis is an assessment of how well a review finding represents the phenomenon of interest. CERQALL provides a systematic and transparent framework for assessing confidence in individual review findings based on four components, methodological limitations, coherence, adequacy of data, and relevance. A fifth component, dissemination bias, may also be important. The approach suggests summarizing evidence in succinct, transparent, and informative summary of qualitative findings tables. This article is the first of a seven-part series providing guidance on how to apply the CERQALL approach. It discusses the rationale and conceptual basis for CERQALL, its aims, development, and main components. The series is intended primarily for those undertaking qualitative evidence synthesis or using their findings in decision-making processes, but is also relevant to guideline development agencies, primary qualitative researchers, and implementation scientists and practitioners. This article was authored by Simon Lewin, Andrew Booth, Claire Glinton, and others. We are article.tv, links in the description below.