ObjectiveTo investigate the relationship between preoperative C-reactive protein (CRP)/albumin ratio (CAR) and National Institutes of Health (NIH) risk classification in patients with gastric stromal tumors.MethodsClinical data of 108 patients with gastric stromal tumors admitted to the First Affiliated Hospital of Kunming Medical University from February 2010 to November 2016 were retrospectively collected. With the median of CAR as the critical value, patients were divided into high CAR group (CAR>0.048) and low CAR group (CAR≤0.048). Then observed the general clinicopathological characteristics and survival status of patients with higher and lower CAR value.ResultsThere were significant differences in NIH classification, tumor diameter, and mitosis between the high CAR group and low CAR group (P<0.05). Compared with the low CAR group, the tumors in the high CAR group had larger diameter, higher mitotic figure, and higher NIH grade. Survival analysis showed that the prognosis of the low CAR group was better than that of the high CAR group (χ2=15.152, P<0.001).ConclusionsCAR is closely related to the malignant index and NIH risk classification of gastric stromal tumors. It can be used as an index for evaluating the malignant degree of gastric stromal tumors, and it is expected to be an important reference factor for clinical NIH risk classification and prognosis.