Restorative proctocolectomy (RPC) is the favorite operation for ulcerative colitis, but it may influence health-related quality of life (HRQL). Our aims were to determine the long-term HRQL of patients and its modifications after a 5-year follow-up and to identify any risk factor for a worse outcome. We enrolled 36 patients submitted to RPC (mean follow-up 8.4 +/- 4.7 years), 36 ulcerative colitis (UC) patients, and 36 healthy subjects. We used a previously validated questionnaire that explored bowel symptoms, systemic symptoms, emotional function, and social function. A series of 17 patients had completed the same questionnaire 5 years earlier. Clinical and surgical factors were investigated. Statistical analysis was performed with Student's t-test, Wilcoxon matched-pairs test, and Fisher's exact test. The scores of the RPC patients were significantly better than those of moderate or severe UC patients, similar to those with remission/mild UC, and higher than those of the controls. The scores of patients interviewed 5 years earlier did not change in the present study, except for patients during the first postoperative year, in whom the scores were now significantly better. The analysis of RPC patients in subgroups showed that the use of drugs, high stool frequency, pouchitis, pelvic complications, and younger age at UC diagnosis worsened the HRQL outcome. We concluded that RPC patients, after a long-term follow-up, had an HRQL similar to that of the remission/mild UC patients. Recently operated patients improved their quality of life mainly because of improved emotional function, and patients who had been operated on for a longer time maintained their HRQL. HRQL is influenced by drugs, stool frequency, pouchitis, postoperative pelvic complications, and age at diagnosis.