BACKGROUND Gemcitabine with platinum is one of the most important first-line treatments for metastatic urothelial cancer (mUC). However, continuation of platinum agents results in cumulative toxicities, such as nephrotoxicity, ototoxicity, and neurotoxicity, which lead to discontinuation of chemotherapy after 4-6 cycles despite a favorable response in the patients. The strategy of maintenance treatment can give clinical benefit to patients, but there is no consensus about maintenance treatment. The aim of this study was to investigate the clinical impact of the gemcitabine maintenance (GEM-m) in mUC patients who achieve disease control from first-line gemcitabine with platinum agents. METHODS A total of 117 patients who showed response to 4-6 cycles of gemcitabine plus cisplatin or carboplatin as the first-line palliative chemotherapy were reviewed between 2014 to 2018. Patients who were treated with GEM-m received a 1,000 mg/m2 dose of gemcitabine on day 1 and 8 for 3 weeks until disease progression or development of unacceptable toxicity. The patients who are not treated with GEM-m were followed up with regular radiologic evaluation. Statistical analyses were performed using the log-rank test and Cox proportional hazards method. RESULTS Fifty-eight patients (49.6%) received GEM-m. The median cycle of GEM-m was 4 (range, 1-12). Six patients (10.3%) in the GEM-m group showed an objective response. A median overall survival (OS) of 11.8 months and 9.6 months was observed for the GEM-m and non-GEM-m groups, respectively [HR 0.621; 95% CI, 0.39-0.97; P=0.026]. Additionally, median progression-free survival (PFS) was 4.6 months and 3.3 months in the GEM-m and non-GEM-m groups, respectively [HR 0.612; 95% CI, 0.41-0.91; P=0.009]. Grade 3 or higher neutropenia occurred in 17.2% of patients in the GEM-m and 1.7% in the non-GEM-m group. CONCLUSIONS Our results suggest that GEM-m can be considered in patients who respond to gemcitabine with platinum. Large-scale prospective study should be warranted.