jats:pThis study investigates the acquisition of grammatical gender in both languages of 21 simultaneous Greek–Dutch bilingual children living in the Netherlands. Greek and Dutch stand on the two opposite sides in terms of frequency and transparency of gender cues. Consequently, monolingual acquisition of gender in Greek is precocious with few overgeneralizations of the default value, neuter, in early stages. In contrast, monolingual acquisition of gender in Dutch is very late with errors in neuter nouns persisting up to the age of 7. Simultaneous Greek–Dutch bilingual children present an interesting test case of crosslinguistic influence in the form of acceleration (Greek affecting Dutch) or delay (Dutch affecting Greek). Children were tested on gender marking on determiners and adjectives in production and grammaticality judgment tasks. Input measures of Greek and Dutch and lexical skills were also considered. Results point to crosslinguistic influence in the form of acceleration of gender discovery in Dutch.</jats:p>