Masticatory improvement obtained by the use of osseointegrated implants (Brånemark System) was analyzed through questionnaires collected from 22 Japanese patients. The questionnaires were designed to assess mastication of different Japanese foods. The postoperative score of masticatory function obtained by analysis of the questionnaires was 90.9, as opposed to the preoperative score of 43.9. A multiple regression analysis indicated that the number of placed implants has no signiiScant effect on the improvement of masticatory function, whereas preoperative performance does. Further, the degree of masticatory improvement showed variation according to the condition of the dental arch opposing the implant prostheses. The group having implant prostheses in the opposing arch showed the highest improvement. Keywords: masticatory function, osseointegrated implants