Background: Gemcitabine as a maintenance therapy is cell cycle-specific with activity in the S-phase; it is used successfully in managing metastatic bladder cancer. Objective: The aim of the current study was to evaluate outcomes of maintenance gemcitabine monotherapy in metastatic bladder cancer patients after standard platinum-based chemotherapy. Patients and methods: A total of 36 patients were included in a randomized controlled clinical trial at Zagazig University Hospitals' Clinical Oncology and Nuclear Medicine Department; 18 patients as a maintenance group (group A) and 18 patients as a control group (group B), who had metastatic cancer of bladder and gave response to 1^st line platinum-based chemotherapy. Results: The visceral metastasis was not statistically significant prognostic parameter (P=0.137). Our study the “6 and 12 months" Progression Free Survival (PFS) in maintenance group (Group A) was 77.8%  and 66.7% respectively versus 42.9% and 0% in control group (Group B) with mean PFS 10.16 months for maintenance group (Group A) and 5.12 months in control group (Group B) which was highly statistically significant different (P-value <0.001). Also “12 and 15 months" Overall survival (OS) was 77.8% and 75.7% respectively in maintenance cases versus 33.3% for both in control group with mean OS (16.05) months among maintenance group and (11.22) months among control subjects which was statistically significant different (P-value 0.008). Conclusion: Gemcitabine as a maintenance treatment showed good results in delaying disease progression and increased overall survival rate among cases who had metastatic transitional cell carcinoma of the bladder received standard platinum-based chemotherapy.