The standards proposed here are designed to serve as a yardstick for public libraries and library systems that serve a population of 150,000 or more and that wish to establish audiovisual services or to strengthen their existing collections and services. The guidelines are intended to supplement the "Minimum Standards for Public Library Systems, 1966." These standards establish the division of responsibilities for audiovisual services among the various units of a library system, develop goals for service, and describe material requirements in detail. Guidelines for staff development are given which prescribe the number and the qualifications of additional personnel necessary for an effective audiovisual program. A description of space and equipment allocations includes specifications for storage and maintenance of various media collections as well as formulas to be used in estimating maintenance costs. Qualitative and quantitative measures which provide the statistics used in planning budgets, allocating staff, and making decisions affecting future service are described. A glossary of terms used in audiovisual library service and an index are included. (JY)