Abstract During the past decade, the importance of a sound microeconomic foundation for aggregate economic analysis has been increasingly emphasized. In this context, a satisfactory theory of bank behaviour appears as an indispensable prerequisite for a clear understanding of the workings of the financial sector of the economy. This has led to the development of a substantial literature attempting to model and explain the behaviour of banking firms. This paper presents a survey and discussion of the various approaches which can be found in this literature. A special effort is made to present an integrated view of the real resource and financial aspect: of banking activities.