BackgroundTemperament or mezaj refers to four different humors differentiating in individuals and, as a result, proposes specific therapy for their diseases.ObjectiveThe aim of this study was to overview the scientific correlation between temperaments in Unani medicine and diseases.MethodsThis study was carried out from March 2015 to February 2016. A computerized search of published articles was performed using PubMed, Google Scholar, Scopus and Web of Science, and Medline databases as well as local and regional resources between 1983 and 2014. The search terms used were temperament, dystemprament, diseases, mizaj, sue mizaj. Additional sources were identified through cross-referencing.ResultsThe result of this study indicated the relationship between dystemprament and incidence of some diseases such as muscle diseases, skin diseases, asthma, palpitation, bipolar disorder, hemodialysis hysteria, hypertension, sinusitis, aging, diabetes, diarrhea. However, further studies are needed to prove the role of dystemprament in incidence of other diseases.ConclusionThe result of this study indicated the relationship between dystemprament and incidence of some disease such as muscle diseases, skin diseases, asthma, palpitation, bipolar disorder, hemodialysis hysteria, hypertension, sinusitis, aging, diabetes, diarrhea. These results are helpful for patients and physicians to change humors toward equilibrium to avoid diseases. Further studies are required to discover the relationship between dystemprament and other diseases.