This inquiry examines whether world knowledge (WK) processing diverges between individuals listening to their native (L1) or their non-native (L2) language. It recorded event-linked brain potentials in L1 and L2 speakers of Spanish while they listened to sentences voiced by native speakers of Spanish. Sentences were either compatible or incompatible with participants’ WK. In addition, participants also listened to sentences in which upcoming words could not be foreseen on the basis of WK. WK violations provoked a late negativity of greater size and duration in the L2 than the L1 group. However, sentences in which WK was not useful concerning word anticipation provoked similar N400 modulations in both groups. These results propose that WK processing demands a deeper lexical search in L2 comprehension than in L1 comprehension.