Recent studies have revealed remarkable interactions between language and emotion. Here, we show that such interactions influence judgments made regarding cultural information. Balanced Welsh–English bilinguals categorized statements about their native Welsh culture as true or false. Whilst participants categorized positive statements as true when they were true, they were biased towards categorizing them as true also when they were false, irrespective of the language in which they read them. Surprisingly, participants were unbiased when categorizing negative statements presented in their native language Welsh, but showed a reverse bias - categorizing sentences as false, even when they were true - for negative statements when they read them in English. The locus of this behavior originated from online semantic evaluation of the statements, shown in corresponding modulations of the N400 peak of event-related brain potentials. These findings suggest that bilinguals perceive and react to cultural information in a language-dependent fashion.