We evaluated the effects of a selective serotonin reuptake inhibitor, paroxetine, on treating tinnitus.Tinnitus patients stratified for the presence of depression and anxiety were studied retrospectively. Fifty-six patients were observed for more than 6 months. They were initially treated with paroxetine only at a dose of 10 mg/day for 2–4 weeks; thereafter, the dose was increased to 20 mg/day. Tinnitus distress was evaluated with the Tinnitus Handicap Inventory (THI) and with visual analog scales (VASs) for tinnitus loudness and annoyance. Depression and anxiety were measured with the Self-Rating Depression Scale (SDS) and the trait section of the State-Trait Anxiety Inventory (STAI). The patients were grouped according to their SDS and STAI scores, and each variable was compared at baseline and the 6-month follow-up. Changes among these variables were also examined to determine whether reduced tinnitus distress was related to the improvement of depression or anxiety. Patients with both depression and anxiety showed better results (decrease in THI, VASs, SDS and STAI scores) than patients with anxiety alone, or patients without depression and anxiety. In patients with depression and anxiety, changes in tinnitus variables and changes in depression and anxiety scores were strongly correlated. In other patients, however, changes in tinnitus variables and changes in depression and anxiety scores were not correlated. These results suggest that paroxetine is effective in treating distressed tinnitus patients with depression and anxiety by reducing their tinnitus severity as well as their depression and anxiety.