In aquatic animals, experimental studies are often used to study the pathogenicity of an etiologic agent; to study interactions between the host, pathogen, and environment; and to evaluate the comparative performance of existing and novel diagnostics. In the latter case, specimens are sometimes collected from animals at different stages of infection post-challenge to demonstrate temporal changes in diagnostic sensitivity post-challenge. Diagnostic accuracy studies should be designed to assess a test’s fitness for a designated purpose, and the design should also inform reporting in peer-reviewed journals. Reported studies should include clear descriptions of purpose and intended application, and authors should discuss the limitations of their results in the context of other available or currently-used tests to facilitate informed decisions by end-users. In human medical research, standards exist for various aspects of diagnostic test research, including guidelines for accurate and transparent reporting and for quality assessment of methodologies in systematic reviews of diagnostic-accuracy studies. Similar standards are required for animal, including aquatic animal, research. It is anticipated that the established criteria, from human clinical research for evaluating diagnostic accuracy studies, can be adapted to develop a standardized set of criteria for the design of field and experimental studies to assess diagnostic accuracy for infectious diseases in aquatic animals.