This systematic review examined the evidence on the extent to which practitioners are equipped to recognize and respond to the indications that a child's needs are likely to be, or are being neglected. This paper examines the methodological issues arising from the review. A systematic process of progressive filtering yielded 112 papers representing primary studies that inform the international research agenda for child neglect. A final dataset of 63 studies was of sufficient quality and usefulness for inclusion. The review raised a number of methodological issues of relevance for research in child protection in general, and on neglect in particular. Researchers and practitioners can benefit from an enhanced understanding of the issues that make neglect difficult to understand. Common issues were identified to inform future research. For example, there was a tendency for studies to use a range of proxy measures rather than direct observation of the outcome of interest, and a wide range of different outcome measures was used. Many of the studies were small scale or retrospective in design. Many studies conflated neglect and other forms of maltreatment, and it was often difficult to extract specific messages for neglect.