Hepatic portal vein aneurysm (PVA) is a rare vascular malformation characterized by localized cystic or fusiform dilation of the hepatic portal venous system. This chapter provides a comprehensive overview of PVA, encompassing its etiology, epidemiology, clinical manifestations, pathology, and imaging features. While the exact cause remains unclear, both congenital and acquired factors contribute to PVA development. The condition primarily affects individuals aged 40–60 and is often asymptomatic, typically discovered incidentally during routine examinations. In some cases, PVA may present with symptoms, such as abdominal pain or jaundice, particularly when associated with underlying conditions like liver cirrhosis or pancreatitis. The chapter emphasizes the crucial role of imaging in diagnosis and follow-up, detailing the characteristic findings across various modalities, including angiography, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound. Key imaging features include localized cystic dilation of the portal vein, with specific enhancement patterns on CT and MRI. The chapter also addresses diagnostic challenges, offering guidance on differentiating PVA from other portal vein abnormalities. Two illustrative case studies are presented, demonstrating the practical application of imaging in PVA diagnosis. The teaching points underscore the rarity of the condition and the paramount importance of imaging in its identification and characterization, providing valuable insights for radiologists and clinicians managing this uncommon vascular anomaly.