To evaluate the prevalence of preoperative anemia and its effect on oncological outcomes in patients undergoing radical cystectomy (RC) due to bladder cancer.Retrospective single-center study with 176 RCs between May 2008 and July 2018. Anemia was defined according to the WHO classification (male130mg/dL, female120mg/dL). Kaplan-Meier test was used to estimate recurrence-free, cancer-specific and overall survival rates. Multivariate logistic regression was used to identify factors associated with overall mortality rates.Overall, 89 (50.6%) patients had preoperative anemia, and 44 of them (49.4%) received neoadjuvant chemotherapy. Anemic patients resulted in higher rates of ASA (ASA2: 54.6 vs. 27.5%; P=.003), ectasia rate previous to RC (41.6 vs. 19.5%; P=.002), treatment with neoadjuvant chemotherapy (49.4 vs. 19.5%; P.001), blood transfusion rate (25.8 vs. 11.5%; P=.015) and pathological stage (pT2: 49.4 vs. 33.3%; P=.03) compared to non-anemic patients. Median follow-up was 27.2 months (IQR 11.12-72.28). Median overall survival (105 vs. 34 months, log-rank; P=.001), cancer-specific survival (89 vs. 61 months; P=.004) and recurrence-free survival (85 vs. 57 months; P=.002) were significantly lower in anemic patients compared to the non-anemic group. In multivariable Cox analysis, preoperative anemia, pT2 and N≥1 were independently associated with overall mortality.Preoperative anemia was common in patients undergoing RC for bladder cancer, and it is related with a worse cancer prognosis. Anemia is a preoperative modifiable factor; we believe that the implementation of Patient Blood Management programs during prehabilitation may have a relevant role in improving the oncological outcomes in these patients.