Objective：To retrospectively validate the Caprini risk assessment model for predicting the risk of peripherally inserted cen－tral catheter（PICC）-related venous thrombosis in tumor patients. Methods：A case-control study was conducted to collect general data and catheterization data from 150 patients who underwent PICC catheterization from 2012 to 2017. Tumor patients with confirmed PICC-related venous thrombosis were enrolled in case group，and according to the tumor type，the 1∶4 paring method was used to enroll catheterized patients without PICC-related venous thrombosis in control group. According to the Caprini risk assessment model，the two groups of patients were scored，recorded，and compared. A multivariate logistic regression analysis was performed to analyze risk factors，as well as the relationship between risk stratification and the risk of PICC-related venous thrombosis in tumor patients. Results：The Caprini score of the case group（7.720±1.768） was higher than that of the control group（6.220±1.097）. In the case group，the proportion of patients with a PICC-related venous thrombosis score of 7 or more was as high as 72%，which was signifi－cantly higher than that of the control group（P=0.000）. Logistic regression analysis with the risk factors as the independent variables showed that severe lung diseases（OR=5.539，95% CI=1.799 to 17.053，P=0.003），history of thrombosis（OR=24.735，95%CI=3.624 to 168.822，P=0.001），and other high-risk factors（OR=6.987，95%CI=2.105 to 23.196，P=0.001） were main risk factors for PICC-related venous thrombosis in tumor patients. Conclusion：The Caprini risk assessment model can effectively predict the risk of PICC-related venous thrombosis in tumor patients and is worthy of clinical promotion.