As a result of the investment pressures caused by neo-liberal policies, project-led practices are becoming increasingly widespread in plan-led planning systems, which, in turn, has directly impacted the planning system. The aim of this article is to examine the impact of such project-led practices within a plan-led planning system through plan changes. This study examines by subject and analyses the spatial distribution of 17,369 plan changes enacted between 2009 and 2018 in Istanbul (Turkey), where the effects of a neo-liberal policy are most evident. The findings of the study demonstrate that these plan changes took place mostly as a result of demands made by the private sector, and that these demands were mostly focused on CBD and newly developing central districts. The results reveal that around a quarter of the plan changes involved alterations in areas reserved for social and technical infrastructure use. They also reveal that spatial outcomes differ according to different plan change typologies.