In recent years, there has been a marked increase in the use of psychiatric case registers for research purposes. Registers are a valuable data asset but there are no standard guidelines for evaluating their use in research. It is becoming increasingly important for researchers who use register data, and journal editors who publish their work, to set benchmarks to assess the quality of a register and its research application. Several criteria that could form the basis of such an evaluative framework are discussed. The discussion is illustrated using a Western Australian e-cohort of half a million children for whom we have assembled comprehensive data cross-linked across a number of administrative registers.