Objectives: To investigate the prognostic significance of the individual conditions contributing to the Charlson comorbidity score in patients selected for radical prostatectomy. Methods: A total of 1910 consecutive patients who underwent radical prostatectomy from 1992 to 2004 were studied. The Charlson score and its contributing single conditions were analyzed, and the patients were stratified into 3 age groups. Comorbid (noncancer), competing (nonprostate cancer), and overall mortality were used as the study endpoints. Mantel-Haenszel hazard ratios and Kaplan-Meier survival curves were calculated. Comparisons were made using the log-rank test. Results: Eleven comorbid conditions were significant predictors of any type of mortality in the different age groups. Eight conditions (congestive heart failure, peripheral vascular disease, cerebrovascular disease, diabetes, hemiplegia, moderate or severe renal disease, diabetes with end organ damage, moderate or severe liver disease, and metastatic solid tumor) were significant predictors of overall mortality. Two conditions (moderate or severe renal disease and metastatic solid tumor) were significant predictors of overall mortality in patients <63 years old. Five conditions (myocardial infarction, congestive heart failure, hemiplegia, moderate or severe renal disease, and diabetes with end organ damage) were significant predictors in patients aged 63-69 years, and 3 (peripheral vascular disease, cerebrovascular disease, and moderate or severe liver disease) were significant in patients aged ≥70 years. Conclusions: In patients selected for radical prostatectomy, the Charlson score can also predict the mortality risk in those >70 years of age. The selection for good risks alters, however, the prognostic weight of the individual comorbid diseases in this age group.