[en] Purpose: To assess morbidity, side effects, and quality of life (QoL) in patients treated for localized prostate cancer with curative aim. Methods and Materials: This descriptive cross-sectional study comprises 154 patients who had undergone definitive radiotherapy (RAD) and 108 patients with radical prostatectomy (PRECT) at the Norwegian Radium Hospital during 1987-1995. At least 1 year after treatment the patients completed several questionnaires assessing quality of life (European Organization for Research and Treatment of Cancer QLQ-C30 instrument [EORTC QLQ-C30]), lower urinary tract symptoms (LUTS): International Prostate Symptom Score (IPSS), or sexuality (selected questions from the Psychosocial Adjustment to Illness Scale [PAIS]). Urinary incontinence and bowel distress were evaluated by ad hoc constructed questionnaires. A control group (OBS) consisted of 38 patients following the watch-and-wait policy. Results: Twenty percent of the patients from the RAD Group had moderate (14%) or severe (6%) LUTS as compared to 12% in the PRECT group. However, 35% of men from the latter group reported moderate to severe urinary incontinence. 'Overall' sexuality was moderately or severely impaired in 71% of the PRECT and 50% of the RAD patients. In the former group high age was correlated with erectile impotency (p < 0.001). In the RAD comorbidity was associated with erectile impotency (p < 0.001). Between 13-38% of the patients recorded moderate or severe bowel distress (blood per rectum: 13%; bowel cramps: 26%; flatulence: 38%), without significant differences comparing patients who had received conventional small 4-field box radiotherapy and patients who had undergone strictly conformal radiotherapy. Despite malignancy and/or treatment-related morbidity, QoL was comparable in both groups with respectively 9% and 6% RAD and PRECT patients, reporting moderately or severely impaired QoL. In the multivariate analysis physical function, emotional function and fatigue were significantly correlated with QoL, whereas sexuality, lower urinary symptoms, and urinary incontinence correlated with QoL only in the univariate analysis. Conclusion: In spite of considerable malignancy and/or treatment-related morbidity QoL was good or only slightly impaired in the majority of patients with localized prostate cancer who presented with stable disease > 1 year after definitive radiotherapy or radical prostatectomy with no difference as compared to the age-matched normal population. Clinicians should be aware of the fact that general QoL dimensions (physical function, emotional function, fatigue) are as a rule of greater significance for QoL than sexuality and lower urinary tract symptoms