This study investigates Italian and French students' grammatical problems while reading in German as an L3 or L4. For the study, we developed a reading test which consists of invented encyclopaedia articles on imaginary animals. These articles enabled us to test various grammatical structures for their receptive difficulty. This paper discusses the relationship between students' reading competence in their other foreign languages (mostly English, French or Italian, or Spanish) and their results on our German-reading test. Our results show that especially the less advanced readers of German benefit from their English-reading competence. With increasing competence in German, the influence of English decreases. Furthermore, correlations between the German-reading test and students' overall foreign-language-reading competence hint at possible advantages of being multilingual. Thus, we will aim at exploring to what extent receptive competences in other foreign languages serve to compensate for weaknesses in the knowledge of the target language, in the hope of complementing existing research on reading in an L3. (Contains 2 figures and 4 notes.)