Without a doubt, linguistic competence represents one of the substantial dimensions of the training process of German language teacher candidates. This article, therefore, aims to determine first the development phases of the foreign language level of German language teacher candidates of Istanbul University and, second, the level of proficiency in German, a future German teacher is expected to achieve during their studies. To this end, the study makes use of the Goethe Zertifikat C1 examination to determine proficiency in the duration of 4 years. The results of the examinations show that there is no significant difference in the linguistic competence between the beginning and the end of the study period of the prospective teachers. The results also constitute the scientific basis of curricular discussions.