The acquisition of noun gender on articles was studied in a sample of 21 young German-speaking children. Longitudinal spontaneous speech data were used. Data analysis is based on 22 two-hourly speech samples per child from 6 children between 1 ; 4 and 3 ; 8 and on 5 two-hourly speech samples per child from 15 children between 1 ; 4 and 2 ; 10. The use of gender marked articles occurred from 1 ; 5. Error frequencies dropped below 10% by 3 ; 0. Definite and indefinite articles were used with similar frequencies and error rates did not differ in the two paradigms. Children's errors were systematic. For monosyllabic nouns and for polysyllabic nouns ending in "-el," "-en" and "-er" errors were more frequent for nouns which did not conform to the rule that such nouns tend to be masculine. Furthermore, children erred in the direction of the rule overgeneralizing "der." Correct gender marking was also associated with adult frequency of noun use. The present data is evidence for the early use of phonological regularities of noun structure in the acquisition of gender marking.