The author used blood flow measurements to guide partial splenic embolization procedures in five patients. The measurements were obtained by time density analysis of contrast medium injections in the splenic artery using digital subtraction angiographic techniques and modified software. The blood flow measurements demonstrated blood flow changes occurring as a result of the embolization. The embolization procedures continued until the blood flow in the splenic artery had been reduced to 50% of its original value. The blood flow measurements appear to predict the amount of parenchymal reduction achieved by embolization and show promise as a method of monitoring these procedures.