Background: Standard treatment for 1st-line mRCC are IO-combinations. Data from real-world collectives are rare. In this multicenter study, we therefore evaluated safety and effectiveness of cabozantinib/nivolumab in Germany. Methods: Data were collected retrospectively from eight GU cancer centres in Germany. Patients (pts) with advanced or metastatic renal cell carcinoma (mRCC) were eligible. Treatment with cabozantinib 40 mg orally + nivolumab 240 or 480 mg i.v. was mandatory and administered according to routine care. Adverse events (AEs) were reported according to CTCAE 5.0. Objective response rate per RECIST 1.1 and Progression Free Survival (PFS) were calculated from start of treatment to progression or death. Descriptive statistics and KM-plots were utilized, where appropriate. Results: 67 suitable pts (62.7% male) with median age of 67.6 years were included. The most common histology was clear cell RCC (ccRCC) in 67.2% (n=45). Nephrectomy was performed in 56.7% (n=38). ECOG 0-1 was 76.1% (n=51). IMDC scores were: 0 in 11 (16.4%), ≥ 1 in 45 (67.1%), missing in 11 pts (16.4%). 29.9% (n=20) required dose reductions or interruptions. Partial response was documented in 46.3% (n=31), stable disease in 32.8% (n=22), and progressive disease in 4.5% (n=3) as best overall response. Data were missing in 14.9% (n=10). Median Follow-up was 8.3 mo, median treatment duration was 6.0 months, PFS rate at 6 month was 81.9% overall (79.3% for ccRCC; 85.9% for non-ccRCC). AEs (all grades) were reported in 82.1% (n=55) and 47.8% (n=32) for grade 3-5. Elevated liver enzymes (40.3%), diarrhea (22.4%) and hand-foot-syndrome (20.9%) were the 3 most frequent AEs of any grade and causality. Conclusions: In this real-world cohort of mRCC pts. cabozantinib + nivolumab was shown to be safe and feasible. While no new safety signals were reported, a reduced dose was frequently utilized. Our data support the use of cabozantinib + nivolumab as a first-line standard. Major limitations were the retrospective data capture and short follow-up of our study.