Although brucellosis is very common in the world and Türkiye, there are no evidence-based guidelines to guide the diagnosis and treatment of the disease. This guide has been prepared by the Turkish Society of Clinical Microbiology and Infectious Diseases to provide evidence-based recommendations to physicians from different specialties interested in the diagnosis and treatment of brucellosis. The recommendations of the Clinical Practice Guide Development Guide of the Infectious Diseases Society of Amer- ica (IDSA) were taken as the basis for preparing this guide. The guideline preparation group determined 20 questions considered to be important in the diagnosis and treatment of brucellosis, and the publications that could answer these questions prepared in PICO (Population/Patient [P], Intervention [I], Comparison [C], Outcome [O]) format, were searched in ULAKBİM Tr Dizin, PubMed, Cochrane databases without date restrictions. The Grading of Recommen- dations, Assessment, Development, and Evaluation (GRADE) Working Group method was used to rank the evidence and determine the strength of the recommendations for each PICO question and for each individual outcome. Me- ta-analyses of comparative clinical studies were performed to answer the PICO questions. Individual participant data (IPD) meta-analyses with data obtained from case reports and case series were conducted in the absence of comparative clinical studies. It is planned to update the recommendations at regular intervals in line with the results of new studies.