One third of all adults report experiencing tinnitus at some time in their lives. Ten percent to 15% have prolonged tinnitus requiring medical evaluation. Classification of tinnitus requires a thorough history and physical examination, supplemented by appropriate diagnostic tests. Tinnitus can be categorized according to its qualities (as described by the patient and matched on the audiometer) and its clinical type (as suggested by probable etiology). Audiologic testing, tinnitus analysis, and occasional radiologic studies assist with classification and direction of treatment planning. The THI is another method of classification that can facilitate the precise monitoring of a patient's progress. By using these tools and standardizing the language, tinnitus studies around the world can become more comparable and patients can be better monitored for treatment response.