The National Preventive Dentistry Demonstration Program (NPDDP) delivered five different regimens of school based preventive dental care to groups of children in 10 American cities between 1977 and 1981. All clinical techniques employed had previously been demonstrated to be both safe and effective in clinical trials. The purpose of the NPDDP was to determine the costs and the effects of these techniques in a real-world setting. This study report details the objectives and methods of the NPDDP. Each of the five regimens is described, and costing definitions and allocation rules are presented. In addition to discussion of the cost analysis methods, consideration is given to the factors which caused variations in the direct costs of care in the 10 different sites. One of the program sites, New York, is described in detail. The relationship between direct and indirect costs is discussed, and the total NPDDP cost experience is summarized. Appended tables, graphs, and commentary provide details of: (1) costs compared as to site, educational materials development, and regimen; (2) use of staff time; and (3) sealants versus topical fluorides in regimen 2. (CB)