This paper is concerned with a number of conceptual and practical issues associated with the use of vouchers to distribute public services. Section 1 proposes a definition of vouchers and considers the position which voucher distribution occupies in the spectrum of possible mechanisms for the production and distribution of public services; this leads into a discussion of the objectives which voucher distribution might promote. Section 2 classifies the contexts in which vouchers might be applied and types of voucher systems. This permits a preliminary mapping of combinations of policy objectives and characteristics of the public service in question onto alternative forms of voucher distribution. Section 3 provides an illustrative review of the use of vouchers in the distribution of public services. Many of the examples discussed are in the field of education, where discussion of or use of vouchers is most developed, but experience of other public services is included where it is available. Section 4 contains conclusions.