BackgroundStudies on the relationship between serum creatinine and the prognosis of prostate cancer have been very limited. The aim of this study was to investigate the role of serum creatinine in the prognostic risk stratification of patients with prostate cancer.Material/MethodsWe identified 1134 eligible patients from the “Prostate Cancer Data Set” in the National Clinical Medical Science Data Center. Patients with prostate cancer were divided high- and low-risk prognostic groups according to prostate-specific antigen levels and Gleason scores and were divided into 5 groups according to serum creatinine quintile: Q1 (<70.1 umol/L), Q2 (70.1–76.8 umol/L), Q3 (76.8–83.4 umol/L), Q4 (83.4–92.1 umol/L), and Q5 (>92.1 umol/L). Multivariate logistic regression and a multiple restricted cubic spline method were used to evaluate the relationship between serum creatinine level and the level of prostate cancer prognostic risk.ResultsOf the 1134 patients with prostate cancer, 134 (11.8%) had a high-risk prognosis. Compared with the Q2 group (the reference group), the lowest serum creatinine levels in the Q1 group and the highest serum creatinine levels in groups Q5, Q3, and Q4 were associated with a high-risk prognosis, and this association remained significant after adjusting for confounders. The multiple restricted cubic spline regression model showed the relationship between serum creatinine level and high-risk prognosis was U-shaped.ConclusionsSerum creatinine level was an independent predictor of high-risk prognosis. Controlling serum creatinine levels between 70.1 and 76.8 umol/L in patients with prostatic cancer may benefit the prognosis of patients with prostatic cancer.