Background/Aim: The systemic inflammation score (SIS) is a promising tool for the evaluation of prognosis. The present study aimed to evaluate the clinical impact of the preoperative SIS status in gastric cancer (GC) patients who underwent curative resection. Patients and Methods: This study retrospectively analyzed 258 patients with primary gastric cancer who received curative treatment at Yokohama City University. The SIS was evaluated before surgery as determined by the lymphocyte-to-monocyte ratio (cut-off value=4.44) and serum albumin level (cut-off value=4.0 g/dl). Results: A high SIS was identified as an independent predictor of overall survival [hazard ratio (HR)=1.784, p