Writing a synthesis text - a text that integrates information from different sources - forms part of the educational curriculum of Dutch secondary education. Representative information on students’ synthesis writing skills is currently missing. Therefore, we carried out a national survey on synthesis writing in the three highest grades of preuniversity education in the Netherlands. The aim was to map synthesis writing on three aspects: text quality, writing process and students’ perspectives on writing. A large and representative sample of 658 students participated. Each participant wrote several synthesis texts. Text quality was rated with benchmark texts; writing processes were registered with keystroke logging software and a questionnaire measured students’ perspectives on writing. Multilevel analyses were used to identify the effect of grade, gender and genre (argumentative/ informative synthesis) on text quality and writing process, and the effect of grade and gender on perspectives. This national survey is a descriptive study providing information on the current state of synthesis writing of Dutch students: how well do students perform on synthesis tasks?, how do they write synthesis tasks?, and what are their perspectives on synthesis writing? Moreover, this study serves as a baseline for future research.