Abstract: Interest group participation in urban development and management is a key factor influencing planning policy-making. Interest groups are often active participants in the process of legislative change. Changes to planning laws are particularly significant, with planning system reform implying increased/decreased development entitlements, obligations, and consultation rights for different stakeholders in the decision process. When the interests of particular groups seem to dominate planning reform processes, the legitimacy of subsequent reforms is often challenged. This paper examines these issues with reference to recent planning reforms in the state of New South Wales (NSW). It examines written submissions, government documents, parliamentary speeches and media reportage, investigating the claims made by different types of interest groups; the strategies each sector used to advance these claims; and how these strategies evolved over time. It also examines which particular interest group sector (across industry and community interests) appeared most influential at different stages in the reform process, focusing on four rounds of public consultation (2011-2013) to provide a narrative framework for analysis. The study shows that the extent of influence of interest groups altered over time in different stages of the planning reform. In particular, business-related or pro-growth interest groups tended to be more professional and efficient in the initial policy design stage. However, after the release of the draft legislation, which addressed the intentions of pro-growth interests, grass-roots community and environment groups quickly responded and established networks to contest the proposed reforms, which ultimately stalled. The case of planning reform in NSW suggests that government actions and apparent policy preferences influence the reactions of interest groups to planning reforms, which in turn mobilise different strategies and tactics in support or opposition to the government’s agenda.