This study compares gender acquisition within determiner phrases between monolingual German children and bilingual children acquiring a Romance language (French, Spanish, Italian) and German or two Romance languages simultaneously. Furthermore, the two languages within the bilingual children are compared to one another with respect to the acquisition of gender. The influence of different factors on gender acquisition is discussed: language dominance, transparency of gender marking and/or reliability of gender cues in the respective languages. It shows that bilingual children can acquire the gender systems in both languages just as monolinguals and that bilingualism per se does not have a delaying effect. In bilingual children, as in monolingual children, German is most problematic in terms of gender acquisition. French represents only slightly more problems than Spanish and Italian, the latter two-gender systems being acquired with ease. Since adult phonological gender rules are characterized by their rather low validity in German and in French, lower accuracy with German gender indicates that the way how gender is marked in the languages influences acquisition more than the validity of gender rules; in German and not in French, gender marking is intertwined with case and number markings. Although our results suggest that gender accuracy depends on the language acquired, some children do not fit into the expected pattern of gender acquisition with respect to the analysed languages. Interestingly, all these children show a language imbalance. Therefore, we claim that the children’s gender accuracy can be predicted on the basis of the language acquired, but language dominance can blur this ranking. Interestingly, it is not the case that gender is delayed in the weak language of the bilingual children; language imbalance has the effect that the child may not tend towards the predicted side of an accuracy ranking (for the weaker language). A further result of this study is that accuracy on neuter gender is lower in bilingual German than in monolingual German, suggesting that the fact that the bilingual children acquire a two-gender system simultaneously with a three-gender system has a delaying effect for target-like neuter marking.