This article contains a general review of existing expert system techniques, terminology, and a history of their development. After a detailed discussion of the methodology of knowledge elicitation and representation, the use of production rules in the knowledge database, search strategies, and uncertainty handling, the application of expert systems to archaeology is discussed. It is concluded that in their present form expert systems have a number of serious practical and theoretical problems. They will require a great deal of further work before being of use in archaeology.