The aim of this study is to investigate the impact of body composition on the risk of portopulmonary hypertension using computed tomography (CT) in patients with liver cirrhosis. We retrospectively included 148 patients with cirrhosis treated at our hospital between March 2012 and December 2020. POPH high-risk was defined as main pulmonary artery diameter (mPA-D) ≥ 29 mm or mPA-D to ascending aorta diameter ratio ≥ 1.0, based on chest CT. Body composition was assessed using CT images of the third lumbar vertebra. The factors associated with POPH high-risk were evaluated using logistic regression and decision tree analyses, respectively. Among the 148 patients, 50% were females, and 31% were found to be high-risk cases on evaluation of chest CT images. Patients with a body mass index (BMI) of ≥25 mg/m2had a significantly higher prevalence of POPH high-risk than those with a BMI < 25 mg/m2(47% vs. 25%,p= 0.019). After adjusting for confounding factors, BMI (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.10–1.33), subcutaneous adipose tissue index (OR, 1.02; 95% CI, 1.01–1.03), and visceral adipose tissue index (OR, 1.03; 95% CI, 1.01–1.04) were associated with POPH high-risk, respectively. In the decision tree analysis, the strongest classifier of POPH high-risk was BMI, followed by the skeletal muscle index. Body composition may affect the risk of POPH based on chest CT assessment in patients with cirrhosis. Since the present study lacked data on right heart catheterization, further studies are required to confirm the results of our study.