This case study reports a systematic review that was conducted as part of a PhD project, which investigated the association between child and adolescent emotional disorder (anxiety/depression) and poor attendance at school. The case study begins with an overview of systematic review methods and some of the benefits of using this method both within the field of medicine broadly, and specifically within the context of a PhD project. I discuss and provide examples of some of the key steps and decisions taken during the design of the systematic review, including what types of studies to include, what population to investigate, what variables to examine, where and how to search for studies, how to screen studies, how to extract data and assess the quality of studies, and how to synthesize the evidence. The case study includes discussion of some of the practicalities of conducting a systematic review, and as well as some of the challenges that were experienced during the process. I finish by providing some practical lessons learned and advice for those about to embark on a systematic review.