Previous research has shown that French subjects, as opposed to Spanish subjects, have difficulties in distinguishing two words that differ only as far as the location of stress is concerned. In French, stress is not contrastive, and French subjects are ‘deaf’ to stress contrasts. In Experiment 1, we replicate this finding with a new and more powerful paradigm for assessing the perception of stress. With this new method, we obtain a complete separation of the two subject populations. In Experiment 2, we test highly proficient French-Spanish bilinguals with the same paradigm. Our findings are that the performance of individual bilinguals is either French-like or Spanish-like. The factor that best predicts the bilingual’s performance is the country in which the subject is born. Consequences for models of bilingualism are discussed.