Organized hematoma is a benign pseudotumor formed by bleeding and inflammation in the maxillary sinus and has conventionally been treated by Caldwell-Luc surgery and preoperative embolization. In recent years, endoscopic surgery has been used, and some reports suggest that preoperative embolization may be unnecessary. However, no study of the treatment methods has been performed with adjustments for patient selection bias. At our department, we have begun to gradually adopt less invasive treatment methods. Herein, we report the differences in the blood loss among the treatment methods, with some discussion of the literature.