We assessed the effect of bilingualism on metacognitive processing in the artificial language learning task, in 2 experiments varying in the difficulty to segment the language. Following a study phase in which participants were exposed to the artificial language, segmentation performance was assessed by means of a dual forced-choice recognition test followed by confidence judgments. We used a signal detection approach to estimate type 1 performance (i.e., the participants' ability to discriminate statistical words vs. foils constructed from the same syllables) and type 2 metacognitive performance (i.e., the ability to discriminate the correctness of the type 1 decisions by confidence ratings). The results showed that bilinguals and monolinguals do not differ in type 1 recognition performance, but across the 2 experiments, metacognitive performance was higher in bilinguals compared with monolinguals. The results show that bilingualism improves metacognitive evaluation of performance in linguistic domains. We suggest that the improvement in metacognitive performance stems from bilinguals' enhanced error-monitoring abilities in language domain, which is also modulated by individual experience.