Objectives: This case report was conducted to introduce the effectiveness of herbal decoction on patients with chronic immune thrombocytopenic purpura (ITP). Methods: We closely observed two patients who were admitted to the Department of Internal Medicine 1 of Kyung-Hee Korean Medical Hospital due to ITP. We gave a herbal decoction to these patients and then analyzed the changes in their general conditions as well as blood test results. Results and Conclusions: The treatment with herbal decoctions was helpful for ITP patients.