Tinnitus (ringing or buzzing in the ear or head) can range from barely noticeable to debilitating. Although a few studies have estimated the prevalence of this condition in adult populations, we know of no population-based estimates of incidence. As part of a population-based study of hearing loss in adults aged 48 to 92 years at baseline in Beaver Dam, Wisconsin, self-reported data on tinnitus were obtained at the baseline examination (1993-1995; N = 3753) and again 5 years later (1998-2000; N = 2800). A person was classified as having tinnitus if their tinnitus was at least moderate in severity or caused difficulty in falling asleep. The prevalence of tinnitus at baseline was 8.2 percent. The 5-year incidence of tinnitus among the 2513 participants at risk was 5.7 percent. Risk factors for prevalent and incident tinnitus were evaluated. The results suggest that tinnitus is a common problem for older adults and is associated with some modifiable risk factors.