International regulations and guidelines strongly suggest that the use of animal models in scientific research should be initiated only after the authority responsible for the review of animal studies has concluded a well-thought-out harm-benefit analysis (HBA) and deemed the project to be appropriate. Although the process for conducting HBAs may not be new, the relevant factors and algorithms used in conducting them during the review process are deemed to be poorly defined or lacking by committees in many institutions. This paper presents the current concept of HBAs based on a literature review. References on cost or risk benefit from clinical trials and other industries are also included. Several approaches to HBA have been discovered including algorithms, graphic presentations and generic processes. The aim of this study is to better aid and harmonize understanding of the concepts of 'harm', 'benefit' and 'harm-benefit analysis'.