Evidence- based medicine as the conscienetious, explicit and judicous use of the current best evidence in making decision about the care of individual patients was first described in 1992 and has gained a growing importance in the last ten years. Evidece based laboratory medicine intergrates into clinical decision making the best available research evidence for the use of laboratory tests with the analytical and clinical expertise and experience of health care professionals and the needs and expectations of patients. Evidence based clinical microbiology, meaning more and better evidence than currently available is needed in the test selection and result interpretation. Interdisiplinary multicentered studies are the best evidence and results are directly related with the patient prognosis and community health. Elimiinating poor or useless tests before they become widely available, removing old tests with no proven benefit from the laboratory repertoire, introducing new tests with proven efficacy, improving the quality and clinical impact of diagnostic test information, reducing health care costs and improving patient outcomes are the major alims. Research evidence of clinical microbiologists and experience of clinicians will maximize the efficiency of test results in patient management.