Background. Pemetrexed is a commonly used treatment for platinum-resistant advanced urothelial carcinoma (UC) based on objective response rates of 8% and 28% in two small phase II studies. To address the discrepancy in reported response rates and to assess efficacy and toxicity outside of a clinical trial setting, we performed a large retrospective analysis of pemetrexed use at Memorial Sloan Kettering Cancer Center. We also investigated candidate prognostic factors for overall survival in this setting to explore whether the neutrophil-lymphocyte ratio (NLR) had independent prognostic significance. Patients and Methods. Patients receiving pemetrexed for platinum-resistant advanced UC between 2008 and 2013 were identified. The Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) were used to determine response rate. Kaplan-Meier and Cox regression analyses were used to examine the association of various factors with efficacy and survival outcomes. Hematologic toxicity and laboratory abnormalities were recorded.