The study evaluated 92 Chinese patients with porto-sinusoidal vascular disorder (PSVD) followed up between January 2019 and June 2024, in whom muscle mass was measured using the psoas muscle index (L3-PMI). Sarcopenia was diagnosed according to age- and sex-specific cut-offs adapted to the Chinese population and found in 17 of 92 patients, representing 18.5%. Patients with sarcopenia more often had a history of bleeding from esophageal varices (88.24% vs. 60.0%). After transjugular intrahepatic portosystemic shunt (TIPS), L3-PMI increased statistically significantly [from 4.84 (3.70–5.44) to 5.10 (4.40–6.10), p = 0.0153]. After endoscopic treatment of variceal bleeding, the cumulative incidence of rebleeding at 1 year was higher in patients with sarcopenia (HR 4.39; 95% CI 1.01–19.10; p = 0.0485). Multivariate Cox regression analysis confirmed that sarcopenia was an independent predictor of 1-year variceal rebleeding. The authors conclude that sarcopenia is common in PSVD, particularly in patients with prior variceal bleeding, may improve after TIPS, and is associated with worse outcomes after endoscopic management of bleeding.