Background: Sunitinib was the standard first-line treatment of advanced renal cell carcinoma (aRCC) for the past decade, but it has been associated with significant hematological toxicities. Immune checkpoint inhibitors (ICI) based regimens have become the new preferred treatment for aRCC in the first-line setting. We conducted a meta-analysis of phase 3 randomized controlled trials (RCTs) to determine the relative risk of hematological toxicities associated with upfront use of ICI-based regimens for aRCC. Methods: We conducted a systematic search at PUBMED, MEDLINE, EMBASE, and meeting abstracts as per PRISMA guidelines from inception until May 2019. Phase 3 RCTs using ICIs in the intervention arm for the first-line treatment of aRCC were included. We used the Mantel-Haenszel (MH) method utilizing random effects model to calculate pooled risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was tested with I² value. Results: Four phase 3 RCTs, CheckMate 214, IMmotion151, JAVELIN Renal 101 and KEYNOTE-426, randomizing 3706 patients were included in the analysis of anemia and thrombocytopenia. CheckMate 214 did not report the number of neutropenia. Hence, other 3 RCTs that included 2624 patients were analyzed for neutropenia. Following regimens were used in the study arms — CheckMate 214: nivolumab+ipilimumab, IMmotion151: atezolizumab+bevacizumab, JAVELIN Renal 101: axitinib+avelumab; and KEYNOTE-426: axitinib+ pembrolizumab. Sunitinib was used in the control arms for all the studies. The pooled RR of any-grade hematological toxicities are as follows — anemia: 0.31 (95% CI:0.24-0.41, P< 0.00001, I²=39%); thrombocytopenia: 0.11 (95% CI: 0.06-0.19, P<0.00001, I²=63%); neutropenia: 0.08 (95% CI: 0.05-0.13, P<0.00001, I²=0%). The pooled RR of grade 3 and higher hematological toxicities are as follows — anemia: 0.14 (95% CI:0.08-0.25, P< 0.00001, I²=0); thrombocytopenia: 0.06 (95% CI:0.02-0.16, P<0.00001, I²=4%); neutropenia: 0.06 (95% CI: 0.02-0.16, P<0.00001, I²=0%). Conclusions: ICI-based regimens have significantly reduced risk of any-grade as well as high-grade hematological toxicities compared to sunitinib in patients with aRCC.