Combined school and public libraries have been studied extensively for more than thirty years. Common advantages and disadvantages, together with typical problems, have been identifi;ed. From the work of researchers in three countries, predictors of success can be articulated: the population served is less than 10,000; a formal planning process involving the stakeholders was undertaken; a written legal agreement for governance, administration, finances, and operations includes guidelines for evaluation and dissolution; a decision-making board or management committee develops policies and procedures and engages and evaluates the director; an integrated facility is conveniently and visibly located, accommodating a variety of groups and resources with a separate area for adults and designated parking; the library is connected with a larger network, regional system, or consortium; the principal has a strong desire for success and teachers support the concept; one highly motivated professional librarian is in charge; there is regular communication and planned cooperation between public library and school staffs; and there are no restrictions on access to resources or on the circulation of materials.