BackgroundSeveral studies have reported that the systemic immune-inflammation index (SII) is associated with the prognosis of patients with urologic cancers (UCs). The aim of this study was to systematically evaluate the prognostic value of SII in UC patients.MethodsWe searched public databases for relevant published studies on the prognostic value of SII in UC patients. Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted and pooled to assess the relationships between SII and overall survival (OS), progression-free survival (PFS), cancer-specific survival (CSS), overall response rate (ORR) and disease control rate (DCR).ResultsA total of 14 studies with 3074 patients were included. From the pooled results, we found that high SII was associated with worse overall survival (OS) in patients with UC (HR 2.58, 95% CI 1.59–4.21). Patients with high SII values also had poorer PFS (HR 1.92, 95% CI 1.29–2.88) and CSS (HR 2.58, 95% CI 1.36–4.91) as well as lower ORRs (HR 0.40, 95% CI 0.22–0.71) than patients with low SII values. In addition, the subgroup analysis of OS and PFS showed that the prognosis of patients with high SII was worse than that of patients with low SII.ConclusionsSII might be a promising noninvasive predictor in patients with UC. However, more samples and multicenter studies are needed to confirm the effectiveness of SII in predicting the prognosis of patients with UC.