This article analyses how urban densification, primarily in relation to ecosystem services, is addressed in comprehensive plans from three cities in southernmost Sweden: Malmö, Lund and Helsingborg. The aim was to investigate and problematise how the comprehensive plans articulate and negotiate how to build dense cities while preserving and enhancing ecosystem services. A qualitative content analysis was performed on the comprehensive plans in use during the study period. The comprehensive plans were all ambitiously formulated. However, three recurrent issues were found. Planners struggled to address the issue of scale: Ecosystem services in the city were addressed when planning for densification, while ecosystem services for the city were either omitted or mentioned in the passing. The timeframe in relation to sustainable urban development was also not clarified. Most importantly, there were profound unclarities regarding priorities. Densification was suggested to provide all positive qualities simultaneously, including enhancing and supporting ecosystem services, which is, from a systems viewpoint, not possible. We suggest that when planning for sustainable cities, based on best available research, politicians should bring the prioritisation process to the fore, to clarify and address how to plan for dense, healthy cities with functioning ecosystem services in a more holistic manner.