Recognising and appreciating linguistic diversity and different cultural identities is an important educational goal for the development of our societies [Council of Europe 2007. From Linguistic Diversity to Plurilingual Education: Guide for the Development of Language Education Policies in Europe. Council of Europe Publishing; 2020. Common European Framework of Reference for Languages: Learning, Teaching, Assessment–Companion Volume. Council of Europe Publishing]. This paper presents the results of a quasi-experimental pre–post control-group study on the implementation of multilingual teaching activities in teaching French as a second foreign language at secondary grammar schools in Germany (in total n = 221 students, a convenience sample of 207th grade classes). Results of analysis of questionnaires and interviews with students show a positive appreciation of multilingual teaching activities, especially among students with migration background who have been raised plurilingually, and an increase in the appreciation of multilingual teaching activities among students who have been raised monolingually in the lingua franca German. Furthermore, the results indicate that the intervention was relevant to students’ intercultural learning in terms of fostering their appreciation of multilingual teaching activities, even though the teaching materials prepared for the study were not implemented consistently in all participating classes.