BACKGROUND: Investigating the effect of newly approved oncological drugs in the real-world is warranted. With emerging novel treatments rapidly being approved for urothelial tract cancers, we aimed to assess real-world data, regarding effect and safety, during the first year after approval of pembrolizumab in Denmark for patients with locally advanced and unresectable or metastatic urothelial tract cancer (mUTC) in the first- and second-line setting. MATERIALS AND METHOD: At the six oncological departments treating mUTC in Denmark, we identified all mUTC patients receiving pembrolizumab during the first year after approval, between March 1, 2018 and February 28, 2019. A retrospective data collection was conducted from January to June 2020. Patient characteristics matching that of the relevant clinical trials for pembrolizumab in first- and second-line treatment-setting, overall survival (OS), progression-free survival (PFS), toxicity and tumor response were assessed. RESULTS: 139 patients were identified, 53 in first-line treatment, 77 in second-line, and 9 receiving third or later lines of treatment. The population was characterized by a majority of males (70%), most patients had ECOG PS 0-1 (60.4%) and primary tumor in the bladder was predominant (90.6%). The overall response rate (ORR) in first-line was 30.2%, PFS was 3,5 months (95%CI 2,3-7,9 months) and OS 9,2 months (95%CI 7,0-20.9 months). For second-line treatment the ORR was 27,3%, PFS 2,9 months (95%CI 2,5-5,3) and OS 9.1 months (95%CI 5,4-12,8 months). Toxicity was comparable to clinical trials without any new toxicities registered. CONCLUSION: Real-world data on response rates, OS, PFS and toxicity for patients with mUTC receiving pembrolizumab in first- and second-line, shows comparable results to clinical trials. This study further establishes immunotherapy as an effective and tolerable treatment for mUTC.