This project assessed how an international service-learning course affected mass communication students' knowledge of professionalism. Using written reflections and focus group transcripts from four courses that took place in Central America, we observed that placing students in immersive environments, where they are able to work on authentic tasks, can enhance their knowledge of specific professional issues. Our observations include managing client relationships, negotiating diverse project teams, and making technology choices appropriate to client and audience. We isolate significant aspects of the course pedagogy and offer suggestions to adapt conventional semester projects to gain some of the affordances of immersion and authenticity.