Idiopathic noncirrhotic portal hypertension is a rare disease of unknown etiology. Patients with idiopathic noncirrhotic portal hypertension have an increased risk of developing portal vein thrombosis and this is especially prevalent when HIV is also present. We describe a unique case of a patient with Idiopathic noncirrhotic portal hypertension associated to HIV, who developed acute portal vein thrombosis that despite anticoagulation transform in portal cavernoma and disappeared completely after five years of follow-up on continuous anticoagulation.