At the end of 2004 Rijeka City Library started a county mobile library service in the region of Gorski kotar and Matulji municipality. Intention of this paper is to present the project of implementing a county mobile library service through several aspects: analysis of a public library network covering Primorsko-goranska County before the county mobile Library started, initiating the project Mobile library service in Primorsko-goranska County, planning and organizing the collections, services and programmes, purchasing the vehicle and equipment, starting the mobile library service, promoting the project, evaluating the project, and the plans for further development. [ABSTRACT FROM AUTHOR]