An unusual case of systemic amyloidosis complicated by portal hypertension is reported. In this condition, portal hypertension is a rare event associated with poor prognosis. In our patient, severe presymptomatic sinusoidal portal hypertension was demonstrated by hepatic vein catheterization and coincided with abundant perisinusoidal amyloid infiltration. Despite these features and the absence of objective response to 20 courses of melphalan and prednisone, the patient was still in good clinical condition 4 years after initial diagnosis. This observation suggests that in primary amyloidosis, the incidence of sinusoidal portal hypertension might be underestimated and also that it may be associated with a relatively good prognosis.