Many students in vocational education and training (VET) have difficulties with reading and writing. To date, there is little research on whether and how the development of VET students' writing skills may benefit from teaching approaches that integrate reading and writing. This study reports results from a semester-long intervention study conducted in Switzerland in 2018/19 (N = 285) in which we investigated the impact of a scenario-based integration of reading-to-write-tasks on the development of VET students' text quality. In the approach, problem-solving processes are set in motion by scenarios representing real- or work-life situations. Reading-to-write tasks form part of the student-initiated problem-solving process, and result in situated argumentative writing. A small experimental intervention effect was found where text quality developed significantly better in the experimental group than in a matched control group (F[subscript 1,178] = 7.40, p < 0.01, Cohen's f = 0.20), as measured in a writing test before and after exposure to the teaching method. Outcomes suggest tangible benefits may result when applying this approach to literacy education in VET, particularly for academically weaker students. We discuss the consequences and implications of these findings, as well as open questions to be addressed by further research.