The Bilingual Aphasia Test (BAT) was designed to assess the residual language capacities of bilingual or multilingual individuals with aphasia. At the present time, the test is available in more than 60 languages. Although its appearance dates from the late 80's, studies to evaluate its psychometric properties are still scarce. The aim of this study was double: (1) to compare language performance in Catalan and Spanish of 56 healthy bilinguals with the Catalan (BAT-Cat) and Spanish (BAT-Spa) versions of the test, and (2) to determine the influence of age and educational level in each language. In general, language performance in Catalan and Spanish was more similar than different. The differences in favour of Spanish can be interpreted in sociolinguistic terms. In general, the regression analysis performed showed that the educational level itself had a greater influence on language performance than age. Except for some cases, the participants of the study achieved the success criteria set by the test manual for each subtest. Finally, the Catalan and Spanish versions of the BAT are comparable and appropriate for their use in our environment; nevertheless, more studies are needed to deepen in their characteristics and properties
