Background: Cisplatin-based combination chemotherapy is considered standard first-line treatment for patients with metastatic urothelial carcinoma. However, cisplatin-based chemotherapy is frequently avoided in elderly patients due to concerns regarding treatment-related toxicities. We analyzed the efficacy, and tolerability, of cisplatin-based chemotherapy in two age groups (< 70 versus ≥ 70 years old). Methods: Individual patient data was pooled from eight phase II and III trials evaluating cisplatin-based first-line chemotherapy in patients with metastatic urothelial carcinoma. Toxicities, treatment delivery, response proportions, and survival outcomes were compared between patients < 70 versus ≥ 70 years old. Results: Of the 543 patients included in the analysis, 162 patients (30%) were ≥ 70 years old. Patients ≥ 70 years old had a significantly lower baseline calculated creatinine clearance (57 vs. 73 ml/min, p<0.0001). All other baseline characteristics, including PS and visceral metastases were well balanced between the two age groups. Patients ≥ 70 years received a median of 1 cycle less of chemotherapy compared with younger patients (median cycles 5 versus 6; p = 0.004). There was no significant difference in the proportions of patients experiencing Grade 3-4 renal failure, febrile neutropenia, or treatment-related death. Response rate among patients ≥ 70 years old was 50% compared to 52% for patients < 70 years old (p=0.65). There was no significant difference in survival between the age groups (p=0.91). The median survival of the patients ≥ 70 years old was 12.1 months compared to 12.8 months for patients < 70 years old. There was no significant difference in survival between age groups when controlling for baseline performance status and/or the presence of visceral metastases. Conclusions: Elderly patients, with adequate renal function and other baseline characteristics suitable for clinical trial enrollment, tolerate cisplatin-based chemotherapy similarly, and achieve comparable clinical outcomes, compared with their younger counterparts. Cisplatin-based therapy need not be withheld from such patients.