Objectives: To assess the effect of blood type on survival outcomes and adverse events (AEs) in patients treated with tyrosine kinase inhibitors (TKIs) for metastatic renal cell carcinoma (mRCC).Materials and methods: Patients who received TKIs as first-line therapy for mRCC between 2008 and 2015 at our hospital were included in the study (n = 136). Patients were divided into 2 groups based on their blood type as 0 and non-O. Survival outcomes and AEs were compared according to blood type. Cox regression models were used for univariate and multivariate survival analyses.Results: Of the 136 patients, 34 (25%) and 102 (75%) had 0 and non-O blood types, respectively. Blood type 0 was associated with an increased number of disease sites. There were no differences between the 2 groups with respect to other baseline characteristics. The progression-free survival in patients with 0 and non-O blood types was 12.1 and 11.6 months, respectively; the overall survival was 34.4 and 24.8 months, respectively. On univariate and multivariate analyses, the ABO blood type was not a significant prognostic factor for progression-free survival or overall survival. Furthermore, the incidences of serious AEs were similar in the 2 blood groups.Conclusions: ABO blood type was not associated with survival outcomes or incidences of serious AEs in mRCC patients treated with TKIs. However, blood type 0 may be associated with an increased number of disease sites. (C) 2017 Published by Elsevier Inc.