['To determine GFR with different methods in patients with first-line chemotherapy for advanced urothelial cancer (UC) and to evaluate the impact of these methods on the estimation of cisplatin eligibility.', 'A database was built retrospectively containing all patients receiving first-line chemotherapy for UC between 2001 and 2012 in one German high-volume center. GFR was calculated with the methods by Cockcroft-Gault (CG), MDRD and CKD-EPI. Measurements of creatinine clearance with timed urine collections were registered.', 'A total of 166 patients were included. All methods of renal function determination yielded consistent results in terms of cisplatin eligibility for 134 patients (80.7 %) and disagreeing results for 32 patients (19.3 %). Twenty-two of these 32 patients with borderline GFR received cisplatin-based chemotherapy. Fifteen of these 22 patients completed at least three cycles. The mean GFR in the mentioned 32 patients was 51.3, 56.2 and 54.2 ml/min with the method by CG, MDRD and CKD-EPI. Three, ten and four patients were estimated cisplatin-eligible with either method. There was a good correlation between MDRD and CKD-EPI (r (2) = 0.92). CG tended to underestimate GFR compared to both MDRD and CKD-EPI. Measurements of creatinine clearance showed a wide distribution in comparison with MDRD (r (2) = 0.002).'] Does the method of GFR determination impact the estimation of cisplatin eligibility in patients with advanced urothelial cancer?