Objective-To determine the impact of comorbidity on survival of bladder cancer patients.Methods-The population included 675 patients with newly diagnosed bladder cancer whose medical information was abstracted from a hospital cancer registry. Adult Comorbidity Evaluation-27, a validated instrument, was used to prospectively categorize comorbidity. Independent variables assessed include comorbidity, American Joint Committee on Cancer (AJCC) stage, grade, age, gender, and race. Outcome measure was overall survival. We analyzed the entire cohort, patients with noninvasive disease, and patients requiring cystectomy. Cox proportional hazards analysis was used to assess impact of independent variables on survival.Results-Median age at diagnosis for the entire cohort was 71 yr and median follow-up was 45 mo. Of 675 patients, 446 had at least one comorbid condition and 301 died during follow-up. On multivariable analysis for the entire cohort, comorbidity (p = 0.0001), AJCC stage (p = 0.0001), age (p = 0.0001), and race (p = 0.0045) significantly predicted overall survival. On subset analysis of noninvasive bladder cancer patients, comorbidity (p = 0.0001) and age (p = 0.0001) independently predicted overall survival, whereas stage, grade, race, and gender did not. On subset analysis of cystectomy patients, comorbidity (p = 0.0053), stage (p = 0.0001), and race (p = 0.0449) significantly predicted overall survival.Conclusions-Comorbidity is an independent predictor of overall survival in the entire cohort of bladder cancer patients, the subset with noninvasive disease, and the subset treated with cystectomy.