This article describes a small-scale research project in two schools using content and language integrated learning (CLIL), one English and one Austrian, where in both cases there had been considerable misgivings about appropriate forms of assessment to match the different kinds of language skill developed in the CLIL process. Teachers were interviewed, possible assessment instruments reviewed and a set of draft benchmarks drawn up. The CLIL approach involves using a foreign language (often English in mainland Europe) as a "medium" for teaching a range of curriculum subjects as well as a subject in its own right.