When working on open mathematical modelling tasks, retelling the task situation in your own words can be used as a comprehension strategy. The retelling can be written or spoken and both strategies have their advantages and disadvantages. In the present study, we investigated the modelling steps carried out during written and spoken retelling when working on open modelling tasks and identified the potentials and challenges that students see in the two retelling strategies. To answer the research questions, the retelling processes of students ( \(N=6\) ) were observed in a qualitative video study and a subsequent interview with questions regarding the retelling was conducted. The results suggest that spoken retelling may have a stronger effect on comprehension and that students seem to favour spoken retelling over written retelling.