Background Treatment options for metastatic renal cell carcinoma (mRCC) are rapidly expanding, and immunotherapy using checkpoint inhibitors is a first- or second-line option for most patients. Objective The objective of the present retrospective analysis was to explore the real-world impact of checkpoint inhibitor-based immunotherapy compared with therapy using other types of targeted therapies using a large real-world database. Methods RenIS, a registry of patients with mRCC was used as a data source. Outcomes were compared for cohorts treated with TKIs or mTOR inhibitors only [targeted therapy (TT) cohort] versus patients who received immunotherapy (IO) using a checkpoint inhibitor in any line of treatment (IO cohort). Data from a total of 1981 patients were extracted from the registry, including 1767 patients in the TT cohort and 214 patients in the IO cohort. Results The median overall survival from the initiation of first-line treatment was 24.5 months versus notreached (p < 0.001) in the TT cohort versus the IO cohort, respectively [HR 0.23, 95% CI (0.17-0.31), p < 0.001]. The probability of 5-year survival was 24.2 versus 67.9% in the TT cohort versus the IO cohort, respectively. Immunotherapy in any line of treatment was associated with a lower risk of death. Overall survival was superior for patients receiving immunotherapy as the first or second treatment line compared with patients treated with non-immunological targeted therapy. Conclusion In real-world patients with mRCC, immunotherapy is associated with significant survival benefit. The present retrospective analysis shows the real-world benefit of second-line immunotherapy in patients previously treated with tyrosine-kinase inhibitors.