There are few papers that have reported on the results of treatment of schizophrenic patients with herbal medicine. Here, we report a 16-year-old male patient with acute schizophrenia and another 27-year-old female patient with chronic schizophrenia treated with herbal medicine. The 16-year-old male patient had disorganized speech, flattened affect, alogia, avolition, and social dysfunction. After he was treated with Gyejigeojakyakgachokchilyonggolmoryeo-tang(Guizhiqushaoyaojiashuqilonggumulitang) for 3 months, his symptoms were no longer present. The 27-year-old female patient had delusions, hallucinations, disorganized speech, disorganized behavior and social dysfunction for 10 years. Although she was treated with many drugs over the 10 years, the symptoms worsened and she had significant medication side effects such as edema, thirst, dysuria, and obesity. After treatment with Gyejigeojakyakgachokchilyonggolmoryeo-tang(Guizhiqushaoyaojiashuqilonggumulitang) for 5 months and subsequent Gyejigamchoyonggolmoryeo-tang(Guizhigancaoilonggumulitang)for 7 months, together with Jawon(Ziyuan) and Moryeotaeksa-san(Mulizexiesan) to treat the aforementioned side effects, the symptoms were almost completely resolved. These findings suggest that schizophrenia may be due to dong, a type of poison defined in oriental medicine. The herbs used to treat ‘Dong’ in oriental medicine are Yonggol(Fossilia Ossis Mastodi), Moryeo(Ostreae Concha) and Chokchil(Dichroa febrifuga). Therefore we used herbal medicine containing Yonggol, Moryeo, and Chokchil to successfully treat these two schizophrenic patients. In conclusion, these findings suggest that treatment of schizophrenic patients, caused by ‘Dong’, with herbal medicine containing Yonggol, Moryeo, and Chokchil might provide good outcomes.