A polling model is a system of multiple queues accessed by a single server in cyclic order. Polling models provide performance evaluation criteria for a variety of demand-based, multiple-access schemes in computer and communication systems. This paper presents an overview of the state of the art of polling model analysis, as well as an extensive list of references. In particular, single-buffer systems and infinite-buffer systems with exhaustive, gated, and limited service disciplines are treated. There is also some discussion of systems with a noncyclic order of service and systems with priority. Applications to computer networks are illustrated, and future research topics are suggested. © 1988, ACM. All rights reserved.