Background: It is frequently implicitly assumed that advantages in language acquisition when learning content through a second language exceed the disadvantages of reduced content acquisition. Aims: Based on cognitive load theory, that assumption was tested experimentally. The theory is concerned with techniques for reducing extraneous working memory load in order to facilitate learning. Materials: This study used a listening task. Methods: French students of Law and Political Science listened to an audio document about the European Court of Humans Rights under one of four experimental conditions: in their native language (French) twice; in a second language (German) twice; first in French, then in German; or first in German then in French. After the listening task, we tested students' understanding of both the German language and of the academic content. Results: Our results indicated that listening to the content in French before listening to it in a second language was beneficial for both content and language learning. In contrast, listening to content in a second language not only depressed content acquisition as is to be expected, but also depressed language acquisition. We discuss the relevance of cognitive load theory to frame learning tasks aimed at teaching content through a second language.