Background: Antineoplastic therapy with the tyrosine kinase inhibitor(TKI) apatinib in patients with advanced or metastatic gastric or gastroesophageal junction adenocarcinoma(GC) has been associated with hypertension (HTN), but little is known about predisposing clinical characteristics. This study describes the real-world association between baseline clinical characteristics and blood pressure (BP) response in patients prescribed apatinib with GC. Methods: 55 GC patients treated with apatinib were collected from the 1st December 2016 to the 1st December 2020 using medical records retrospectively. Outcomes were defined using the National Cancer Institute’s Common Terminology Criteria for Adverse Events v5.0. Univariate and multivariable logistic regression were used to investigate potential clinical risk factors. Results: 45.45% of patients were evaluated for apatinib-related HTN and Grade 3 HTN occurred 16.36% of patients. Median maximal systolic blood pressure (SBP) during apatinib treatment was 153 mmHg with median time to event of 25 days. New-onset HTN occurred in 10/33 (30.30%) patients. pre-existing HTN(odds ratio [OR]: 4.155; 95% confidence interval [CI]: 1.252-13.787; p =0.020 was key independent risk factors associated with apatinib-related HTN. Conclusions: More thorough BP monitor prior to starting apatinib especially in patients with pre-existing hypertension may reduce cardiovascular risk.