Diagnostic images are reviewed in multiple settings and the specific requirements for diagnostic display devices are outlined dependent on whether this is primary diagnostic work, clinical review work or mobile review of radiology images. The importance of the viewing environment – physical and ergonomic – should always be taken into consideration alongside the performance of the diagnostic display devices. The current guidance incorporates relevant areas of and supersedes Picture archiving and communication systems (PACS) and quality assurance, second edition, which is now withdrawn.