Intended for use in countries planning the establishment of new union catalogs, as well as in countries with long established traditions of library resource sharing, this document provides guiding principles and outlines standard methods and practices for the compilation of union catalogs of serials. Following definitions of relevant terminology and a discussion of the objectives, uses, and characteristics of union catalogs, guidelines are given in six areas: (1) the decision to establish a union catalog, including assessment of the general circumstances and the financial and technical resources available; (2) the establishment of the catalog, including aspects of policy, content, the legislative framework, and available resources; (3) organization and management of the catalog, particularly the responsibilities of an editorial center; (4) the content of bibliographic records, including both bibliographic and holding/lending information; (5) catalog compilation and maintenance, including its arrangement, access points, and filing system; and (6) production and publication of the catalog in printed, microform, or computerized format. A brief note on the updating of union catalogs and a list of 18 references conclude the publication. (ESR)