Spatial plans shape land-use changes, which in turn are main drivers of anthropogenic ecosystem alterations, therefore influencing the ecosystem services (ES) delivered by a given territory. However, integration of the ES concept in policies and plans is reported as poor in literature. The main goal of this research is to gain insight on the views and perceptions of Portuguese regional spatial planners regarding the ES concept and its integration in spatial plans. For that we designed and administered a questionnaire survey aimed at practitioners and decision-makers from Portuguese regional spatial planning authorities. The survey focused on issues such as the level of awareness and knowledge of the ES concept among planners, the perceived level of current ES integration in regional spatial plans and corresponding strategic environmental assessments, the main factors that either facilitate or obstruct that integration, or the level of importance given to ES integration in the planning process. Findings show that planners know the ES concept, they consider it as important to be integrated in spatial planning and, interestingly, that it is already rather integrated in existing plans. They believe that planning teams and authorities have skilled human resources for ES integration. However, they revealed a low knowledge on the main initiatives intended to push ecosystem services into the political agenda, like for example the Millennium Ecosystem Assessment. The questionnaire used can be easily transferred into other spatial planning contexts to draw, e.g. a broader European picture on ES integration in spatial planning.