Several studies (e.g., Ház 2005) have found German to be easier to understand for Dutch listeners than Dutch for German listeners. This asymmetry has been attributed to the fact that German is an obligatory subject in Dutch secondary school and that many Dutch people watch German television. In contrast, it is much less common for German children to learn Dutch at school and for German people to watch Dutch television. It cannot be excluded, however, that in addition to the extralinguistic factor of language contact, linguistic factors also play a role in the asymmetric intelligibility between German and Dutch. The present study aimed at gaining insight into the phonetic-phonological factors playing a role in Dutch-German intelligibility at the word level for speakers of the respective languages in a first confrontation (i.e., assuming no prior language contact). We presented highly frequent Dutch and German cognate nouns, recorded by a perfect bilingual speaker, to Dutch and German children between 9 and 12 years in a word translation task. The German and Dutch children were comparable in that they did not know the other language or a related dialect and expressed equally positive attitudes towards the other language, its speakers and the country. It was thus ensured that language contact and language attitude could not play a role in the present study. Our results revealed that the Dutch subjects were significantly better at understanding the German cognates (50.2% correct translations) than the German subjects were at understanding the Dutch cognates (41.9%). Since the relevant extra-linguistic factors had been excluded, the asymmetry must have a linguistic basis. A thorough analysis of the 16 cognate pairs with an asymmetry larger than 20% showed that (combinations of) neighbors (lexical competitors), phonetic detail and asymmetric perceptions of corresponding sounds play a major role in the explanation of the asymmetry.