This article reports on an investigation of the challenges and benefits of university students taking a degree course in a language other than their mother tongue. Our study was conducted from the point of view of the non-native students themselves, and our primary concern was the role of language. We investigated the academic achievement of German students studying in a Dutch-English academic environment. Dutch is the main language of instruction, and English the main language of the literature used. In search of predictors for successful learning of Dutch (our first research question), LexTALE tests were administered to determine linguistic competence in the students' first language, German, and their second language, English. In addition, we collected data on their educational background and language learning history. None of the LexTALE scores stood out as "the" predictor for success in learning Dutch; German was a slightly better predictor than English. The best predictor appeared to be the students' general educational level, expressed in mean grades for final exams in secondary education. We then studied the role of proficiency in the foreign languages needed for academic success. Language data on L3 Dutch were gathered at the start and were compared to study results after the first six months and at the end of the first year. The level of Dutch as a second language correlated with study results, expressed in ECTS; the correlation was even higher with mean grades on exams. This indicates that language proficiency does play a role in study success.