AbstractPartial splenic embolization (PSE) has developed as an alternative to surgical splenectomy, mainly to improve hypersplenism and esophagogastric varices in cirrhotic patients. We proposed the novel concept that splenic infarction volume, rather than the splenic infarction ratio, is essential for patients receiving PSE. A splenic infarction volume between 388 and 540 mL is suitable for a sufficient increase in platelet count and less severe PSE‐related complications. When restricted to patients with massive splenomegaly >700 mL, the noninfarcted volume of the spleen plays an important role in increasing platelet counts. Based on the splenic volume concept, PSE or laparoscopic splenectomy should be selected. Partial splenic embolization is effective for cancer patients with hypersplenism. Hypersplenism can occur due to portal vein congestion by thrombosis or tumor thrombosis, and hepatic sinusoidal obstruction syndrome after oxaliplatin‐including chemotherapy other than liver cirrhosis. Therefore, PSE has been emphasized as a pretreatment intervention for invasive treatments for cancer patients and is applied synchronously with systemic chemotherapy or chemoembolization for patients with liver malignancies. It was reported that additional PSE on chemoembolization can prolong progression‐free survival for patients with hepatocellular carcinoma. Moreover, PSE can improve liver function and fibrosis, promote liver regeneration, and activate host immunity. Partial splenic embolization can result in thrombocytosis (<200 × 109/L), but this platelet count is unlikely to promote cancer progression. Partial splenic embolization can improve hypersplenism caused by various factors related to the patient's comorbidity and cancer treatment. Our splenic volume concept helps identify appropriate treatment procedures. A proper understanding of PSE and its dissemination is strongly required.