An important aspect of language assessment development is to create tasks that engage the competencies required in the target situation. For this reason, English-medium university entrance tests increasingly feature integrated reading-into-writing tasks as a way of enhancing target domain representation. Despite increased use of this task type, studies outlining the development of rating scales designed specifically for integrated assessments are rare. To this end, the study reports on the development of a rating scale to assess performance on an integrated reading-into-writing task as part of an English-medium university entrance test in Turkey. The authors discuss an iterative process of rating scale development involving examiner feedback, a focus group and many-facet Rasch measurement to validate the rating scale. The results indicate that the scale represents the integrated construct appropriately and reliably separates test candidates into different levels of ability. © 2022 Walter de Gruyter GmbH, Berlin/Boston.