Nivolumab-ipilimumab has become the standard of care in the frontline setting for intermediate-/poor-risk metastatic renal cell carcinoma (mRCC). This regimen is associated with survival improvement but significant toxicity. Anti-programmed cell death protein 1(PD-1)/programmed death-ligand 1(PD-L1) monotherapy may provide response and offers a better safety profile. In this context, nivolumab-ipilimumab has been postulated as a rescue treatment after anti-PD-1/PD-L1 therapy. Recent retrospective data has shown positive results, and several nonrandomized clinical trials (NRCTs) have evaluated this strategy. Therefore, we performed a meta-analysis of available NRCTs to clarify the efficacy and safety of salvage nivolumab-ipilimumab in mRCC after prior anti-PD-1/PD-L1 monotherapy. We searched PubMed, Medline, Embase, and the Cochrane Central Register of Controlled Trials to identify clinical trials investigating the efficacy and safety of salvage nivolumab-ipilimumab after prior anti-PD-1/PD-L1 in patients with mRCC. Only phase II NRCTs were available for the analysis. The pooled effect of single proportions with a 95% confidence interval (CI) was used as the measure of effect (overall response rate [ORR] and incidence of grade ≥ 3 adverse events). Four studies accounting for 237 patients were included. All patients received prior anti-PD-1/PD-L1 monotherapy. The pooled ORR of salvage nivolumab-ipilimumab after prior anti-PD-1/PD-L1 failure was 10.0% (95% CI, 6%-14%; I = 41%; P = .17). The incidence of grade ≥ 3 irAEs was 27.0% (95% CI, 20%-35%; I = 0%; P = .56). The results of this analysis suggest that the use of salvage nivolumab-ipilimumab in mRCC after prior anti-PD-1/PD-L1 has limited activity with a 10% ORR, and a non-negligible toxicity with 1 of 4 patients developing grade ≥ 3 immune-related adverse events.