To discover the characteristic dental treatment of handicapped patients, a committee of the Japanese Society of Pediatric Dentistry dealing with problems in dental treatment of handicapped patients sent a questionnaire to Departments of Pediatric Dentistry of the 29 dental colleges and schools of dentistry nation-wide, to universities and child centers with a division of dentistry for handicapped children, as well as to general practitioners randomly selected who were members to either of the Society of Dentistry for Handicapped Patients or the Society of Pediatric Dentistry. Items of the questionnaire included (1) name and location of the dental institution, (2) the year of establishment of the institution, (3) working hours of the clinic, (4) the number of chairs exclusively used for the handicapped patients, (5) the number of staff members, (6) the sexes and ages of handicapped patients, (7) details of the dental treatment, (8) methods of anesthesia treated, (9) use of restraining devices, (10) name of general diseases, and (11) residency status in institutions for handicapped patients. Responses to the questionnaire were obtained from 93 institutions involving 4,386 patients. The results of the questionnaire were analyzed comparativery among nine groups providing dental care including (1) Departments of Pediatric Dentistry, (2) Depatments of Dentistry for the handicapped patients, and (3) Departments of Oral Surgery in university/college hospitals, (4) hospitals of child centers, (5) hospital clinics for the handicapped patients, (6) public centers, (7) centers of the community of dentists, (8)general practitioners, and (9) others. We report here the detailed analysis of the comparative results.