The two experiments presented in this paper tested the effects of gender agreement on lexical decisions by presenting grammatically congruent and incongruent noun phrases in different context-target combinations. In the first experiment, a condition in which the target noun was directly preceded by a gender-marked determiner was contrasted with a condition in which an invariable adjective intervened between the determiner and the target. In the second experiment we compared the effects of gender marking in the latter condition with a condition in which both the determiner and the intervening adjective carried an overt gender mark. It was shown first, that lexical decision times to target nouns were longer for incongruent context-target combinations than for a congruent baseline condition. Second, the magnitude of the congruency effect was stronger when the target noun was preceded by a determiner plus an invariable adjective than by a determiner only. Third, the magnitude of the effect did not vary according to whether or not the intervening adjective carried a phonetically realized mark of gender. These results are discussed in terms of the automaticity of syntactic processes, and the crucial role of determiners in setting agreement features for the entire noun phrase when processing languages such as French.