This article examines recent initiatives to reform the planning system in the UK. It adopts a Regulationist approach to locating the reform initiatives in a political-economic context and assessing their scale and nature. The main concepts and arguments of the Regulationist approach are summarized, then applied in interpreting three main phases of UK planning 'modernization'. It is concluded that planning reform has been conducted in a poorly understood context, whilst shackled to the legacy of its immediate post-war origins. Consequently, key elements of the UK planning system appear increasingly adrift from contemporary conditions, and outmoded in relation to new imperatives. The Regulationist approach offers a point of departure in the search for planning frameworks addressed to contemporary challenges. © 2005 Taylor & Francis.