Relying on a model of community developed by Spiro (1958), the article examines prisons as functioning communities seeking to solve their problems. It is argued that much of the theory building done concerning prison systems has been within two dominant perspectives -- importation and functional. This article, however, views prisons as more complex social systems that, unlike normal communities, face inherent impediments to identifying and solving their basic problems. Finally, implications from this model for prison research are discussed. 38 references. (Author abstract)