This is a reprospective study on the care of odontogenic infections in admission patients with geriatric diseases. The study was based on a series of 480 patients at Dong San Medical Center, Wonju Christian Hospital and Il San Health Insurance Hospital, From Jan. 1, 2000, to Dec. 31, 2002. The Obtained results were as follows: 1. The systemic malignant tumor was the most frequent cause of the geriatric diseases with odontogenic infectious diseases, and refractory lung disease, systemic heart disease, type II diabetes mellitus, cerebrovascular disease, bone & joint disease, senile psychologic disease were next in order of frequency. 2. Male prediction(57.5%) was existed in the odontogenic infectious patients with geriatric diseases. But, there were female prediction in senile psychologic disease, systemic heart disease and cerebrovascular disease. 3. The most common age group of the odontogenic infectious patient with geriatric disease was the sixty decade(47.9%), followed by the seventy & eighty decade in order. 4. In the contents of chief complaints on the odontogenic infectious patients with geriatric disease, peak incidence was occurred as toothache(52.7%), followed by extraction wish, tooth mobility, oral bleeding, oral ulcer, fracture of restoration, gingival swelling in order. 5. In the diagnosis group of odontogenic infectious diseases, periodontitis, pulpitis & periapical abscess were more common. 6. In the treatment group of odontogenic infectious diseases, the most frequent incidence(34.2%) was showed in primary endodontic treatment (pulp extirpation, occlusal reduction and canal opening drainage) and followed by scaling, incision & drainage, only drugs, pulp capping, restoration in order.