The implementation of clinical information systems and electronic medical records does not have a good track record. It is estimated that more than 50% of implementations fail. A review of electronic health information system (EHIS) models incorporating clinical information systems and electronic medical records was undertaken to determine the models developed and applied in health. Twenty one health and five non-health models were identified. The non-health models were included as a number of health models were derived form these. The findings and evaluation of the models has identified varying contents and results. The models identified were assessed to determine how these related to each other, whether models were tested and how, if benefits were identified and if costsavings were projected or realised. This review of EHIS implementation models has identified a need for clear definition of terms used, careful categorisation and for models to be comprehensive, extensive and rigorous if successful outcomes are to occur.