Background: The neutrophil to lymphocyte ratio (NLR) is reported to be a prognostic factor in multiple malignancies. However, its prognostic value in patients with gastrointestinal stromal tumors (GISTs) remains controversial. This study aims to evaluate the prognostic value of preoperative NLR in GISTs. Methods: MEDLINE, EMBASE, and, Cochrane databases were searched until February 2017. Eligible articles were defined as studies assessing the prognostic role of preoperative NLR in GISTs. The end points were overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), and clinicopathological parameters. Pooled hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed-effects/random-effects models. Results: A total of eight studies comprising 1676 patients with GISTs were included. Elevated NLR had an association with decreased DFS/RFS (HR: 2.18, 95% CI: 1.30-3.67, P = 0.003), but not OS (HR: 1.74, 95% CI: 0.63-4.84, P = 0.29). The findings from most subgroup analyses were consistent with those from the overall analysis. Moreover, high NLR was significantly correlated with male, stomach lesion, tumor size (> 5 cm), tumor rupture (+), tumor recurrence (+), mitotic index (> 5/50 HPF), and NIH risk category (high/intermediate). Conclusions: Elevated preoperative NLR may be an unfavorable prognostic biomarker in patients with GISTs.