BACKGROUND: Recent studies have investigated the role of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic inflammation index (SII), and prognostic nutritional index (PNI) on prognosis for various malignancies. However, the value of these markers in determining the prognosis for gastrointestinal stromal tumors (GIST) remains controversial. We investigated the effect of NLR, PLR, SII, and PNI on 5-year recurrence-free survival (RFS) in patients with surgically resected GIST. MATERIALS AND METHODS: We retrospectively analyzed patients (n=47) who had undergone surgical resection for primary, localized GIST at a single institution between 2010 and 2021. The patients were divided into two groups according to the recurrence status in the 5-year period as 5-year RFS(+) (patients with no recurrence (n=25) and 5-year RFS(-) (patients with recurrence (n=22) groups. RESULTS: In univariate analyses, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), tumor localization, tumor size, PNI, and risk category were significantly different between the RFS(+) and RFS(-) groups while NLR, PLR, SII were not. Multivariate analyses revealed that only the tumor size (HR =5.485, 95% CI: 0.210-143.266, p=0.016), and PNI (HR= 112.020, 95% CI: 8.755–1433.278, p<0.001) were independent prognostic factors for RFS. The patients with a high PNI (≥46.25) had a higher 5-year RFS rate than the patients with low PNI (<46.25) (95.2% to 19.2%, p<0.001). CONCLUSION: A higher preoperative PNI is an independent positive predictor for 5-year RFS for patients with surgically resected GIST. However, NLR, PLR, and SII have no significant effect.