Objectives: To externally review a nomogram developed to predict the 10-year survival probability of men selected for radical prostatectomy. Methods: A total of 1910 consecutive patients who underwent radical prostatectomy from 1992 to 2004 were studied. The mean age was 64.2 years; the mean follow-up for the surviving patients was 6.3 years. The patients were classified according to age and the Charlson comorbidity score. The 10-year survival probability was estimated for each individual patient, applying a recently published nomogram incorporating these 2 variables. The survival rates estimated by the Kaplan-Meier method and the mean values of the nomogram-predicted survival probabilities were compared using 1-sample Wald tests. Subgroup analyses were done after stratification by age and Charlson score. Results: Even including the prostate cancer-related mortality (accounting for 5.1% at 10 years), the 10-year overall survival rate in our sample was somewhat greater than predicted by the nomogram (84.9% vs 81.9%, P = .0222). Subgroup analyses revealed that this difference was attributable to a greater than predicted survival in patients with a Charlson score of 0 and aged ≥70 years (87.9% vs 74.7%, P < .0001). In contrast, in the other subgroups, the predicted and Kaplan-Meier estimated survival rates did not differ meaningfully. Conclusions: Clinicians using this nomogram should be aware of a possible underestimation of survival in healthy men aged ≥70 years selected for radical prostatectomy.