Aim: To examine the prognostic value of the platelet-to-lymphocyte ratio (PLR) in the adjuvant renal cell carcinoma setting. Materials & methods: Patients received adjuvant sunitinib (50 mg/day; 4 weeks on/2 weeks off) or placebo. The primary end point was disease-free survival (DFS). Results: In 609 patients, DFS was similar for baseline PLR <140 versus ≥140 overall (median: 6.4 vs 5.9 years; hazard ratio: 0.9; 95% CI: 0.7-1.2). A ≥25% decrease in PLR at week 4 overall was associated with longer DFS versus no change (hazard ratio: 0.8; 95% CI: 0.6-1.0). Conclusion: Baseline PLR was not prognostic for DFS with adjuvant sunitinib treatment in patients with renal cell carcinoma. Clinical Trials Registration: NCT00375674 (ClinicalTrials.gov).