This methodological guidance paper discusses the craft of reviewing qualitative research for a systematic review. Qualitative research is an expansive and wide-ranging domain that includes research from different disciplines, for different purposes, following different methodological traditions, and employing a variety of data collection and analysis methods. While many aspects of reviewing qualitative research are similar to reviewing quantitative research, the essay focuses on five central tasks: (1) clarifying purpose(s), (2) defining research quality, (3) situating the research in relevant contexts, (4) adding it up, and (5) practicing reflexivity--that every reviewer of qualitative research engages in.