In this chapter, we acknowledge that there are many practical challenges for ensuring that studies using qualitative synthesis are rigorous and that the findings are plausible. Many of these difficulties are inherent in qualitative methods generally and thus can be exacerbated in qualitative synthesis of these studies. Many of them are unique to the process of synthesis. In this chapter, therefore, we attempt to offer suggestions for establishing the plausibility of a qualitative research synthesis. We begin the chapter by describing some of the common misconceptions about how credibility may be established in syntheses. We then describe our ideas for ensuring rigour and following plausibility, which we necessarily previewed in Chapters 3 and 4 as we described the processes of synthesis. Here, we elaborate on many of these concepts providing further details about then. We additionally provide a framework for thinking through the processes. Furthermore, we outline concrete ideas and suggestions for how the framework may be applied in the practice of synthesis.