Background: Depression in all populations is associated with profound decrements in quality of life, social functioning and economic productivity. However, in the case of Post Natal Depression, the adverse consequences are felt beyond the individual with depression affecting the family and development of the infant. The use of screening and case finding instruments has been proposed in the perinatal period. We have conducted a review of the effectiveness of this approach using state-of-the-art diagnostic review methods. This has provided us with unique insight into the potentials and pitfalls of extending the methods of diagnostic reviews into this new area. Objectives: 1. To produce summaries of the key psychometric properties of available PND identification strategies; 2. to identify the difficulties of applying evidence synthesis to psychometric instruments, where shifting cut points and diagnostic thresholds, with important sources of anticipated between-study heterogeneity are the norm (rather than the exception). Methods: We used random effects bivariate meta-analysis to produce summary receiveroperator characteristic (sROC) curves. We also explored heterogeneity with meta-regression. Results: Sixty-four studies validated PND identification strategies against a standardised diagnostic interview conducted according to internationally recognised criteria. The most frequently reported identification strategy, the EPDS, had pooled sensitivities and specificities ranging from 0.31 to 0.96 and 0.45 to 0.99, respectively. Methodological concerns arose regarding pooling when there are clear and multiple cut points and ‘threshold effects within thresholds’. Conclusions: Pooled estimates of sensitivity and specificity varied greatly depending on the cut point used and the type of depression investigated. Methodological issues were identified, which need further investigation, when undertaking diagnostic accuracy studies using psychometric instruments. The implications for the conduct of diagnostic reviews of psychometric instruments using proposed Cochrane methods will be discussed in detail.