The aim of this study was to highlight the clinical characteristics of tinnitus and to attempt a quantitative assessment in relation to any underlying etiologies. We undertook to study a population of 123 patients attending a tinnitus clinic between 1998 and 2000. Their answers on a questionnaire allowed detailed evaluation of the characteristics of tinnitus, including such variables as the circumstances in which the tinnitus was first noticed and evaluation of its intensity and frequency. The patients each underwent a full neurootological examination with the aim of diagnosing an etiology. The great majority of tinnitus patients had an endocochlear deafness and, among these patients, acoustic trauma, endolymphatic hydrops, and presbyacusis were the commonest diagnoses (32%, 32%, and 23%, respectively). Of these patients, 93.7% with noise trauma an 86.9% with presbyacusis described their tinnitus as a stable, high-pitched whistling. Those patients with active Ménière's disease or Ménière's-like syndrome described a low-pitched buzzing tinnitus. Analysis of those patients with a stable high-pitched tinnitus associated with a high-frequency hearing loss shows a statistically significant correlation between the elevation of the audiometric thresholds and the loudness of the tinnitus. For a large majority of patients with tinnitus, therefore, audiometry provides an indirect test for evaluating the tinnitus.