A 30-year-old pregnant woman developed postpartum HELLP syndrome. Abdominal computed tomography revealed a high-density vessel structure in contact with the right kidney and connected to the right ovarian vein, suggesting thrombosis in the right inferior renal capsular vein (RCV). RCV thrombosis is a rare thrombotic disorder in postpartum women, and hypercoagulability related to the pregnancy complications may be the predisposing factor. The potential risk for pulmonary embolism in the rare pregnancy-related thrombosis should be recognized.