The Swedish education system has undergone major restructuring since the early 1990s. The new policy, including e.g. decentralisation, accountability, school choice and a tax-funded voucher system, has led to an expanding "school market". This article explores how upper secondary school principals perceive the increased competition among schools and its impact on their work and the school organisation. The data emanate from interviews with principals at eight schools in five municipalities. The presence of the market in everyday work is perceived as a reality, even if its significance varies. The principals argue that competition increases the staff's efforts and improves school development. However, it is also perceived as problematic since it causes increased stress and uncertainty. The principals' professional identities seem to have changed from a pedagogical role to a more economics ditto. Most principals are pragmatic and make efforts to handle the new policy context the best they can.