Three techniques of transcatheter splenic arterial occlusion were evaluated in dogs. Angiographic, hematologic, and morphologic studies were done up to 9 weeks postocclusion. All animals showed hematologic changes characteristic of depressed splenic function; the degree and duration of these changes depended upon the technique. Alterations in histology including vascular congestion, infarction, and fibrosis, were also dependent upon the method used and the time elapsed after occlusion. Celiac angiography demonstrated the extent of collateral circulation and degree of recanalization of the occluded vessels. Potential clinical applications are discussed.