The Oral Immunology/Microbiology Research Group was founded in 1991 as a means of promoting collegial interaction and collaboration among individuals interested in the immunology and microbiology of the oral cavity, particularly as related to oral disease (dental caries and periodontal disease). Formed in response to a general perception that large meetings such as the IADR/AADR General Sessions do not provide a forum suitable for intimate discourse and collaboration, the OIMRG is comprised of more than seventy investigators representing thirty-nine universities, research centers and commercial organizations in the U.S. and abroad. Once each year the group convenes for an annual meeting which consists of three scientific sessions, each focusing upon a distinct area of oral immunology and microbiology. It is primarily, but not exclusively, through the annual meeting that the objectives of the Oral Immunology/Microbiology Research Group are achieved. These objectives include the following: 1. To foster interaction and collaboration among scientists interested in oral immunology and microbiology. 2. To promote information exchange and collaboration between academicians and their colleagues in the private sector who are engaged in basic and clinical studies pertaining to oral health and disease. 3. To provide a forum through which new investigators establish contact with representatives of federal and non-federal agencies which may be potential source of funding for future studies. The 15th-annual meeting of the Oral Immunology/Microbiology Research Group (OIMRG) has been scheduled for February 4-7th, 2005 at the Caribe Hilton in San Juan, Puerto Rico. Session topics will include a) host responses to oral bacteria, b) mechanisms of microbial pathogenesis employed by oral bacteria and c) mechanisms of host mediated injury to oral tissues. Three guest lecturers have been invited, one discussing a topic related to the broad area of host immunity, one pertaining to bacterial virulence factors and the other describing host genetics. Perpetuation of the OIMRG and its annual meetings greatly enhances the goals of the OIMRG as related to oral health and disease.