In the article entitled “The Usefulness of the Modified Frailty Index for Muscle-Invasive Bladder Cancer Patients Treated with Radical Cystectomy” published in Current Urology 2020;14(1):32–37 (DOI: 10.1159/000499263), the following Statement of Ethics was omitted: “All data were obtained based on anonymous personal data for which no Institutional Review Board approval was required according to local agreements. An informed consent was taken before treatment. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.” We apologize for this error and any inconvenience this may have caused.