In this study we explore whether world knowledge (WK) processing differs between individuals listening to their native (L1) or their non-native (L2) language. We recorded event-related brain potentials in L1 and L2 speakers of Spanish while they listened to sentences uttered by native speakers of Spanish. Sentences were either congruent or incongruent with participants’ WK. In addition, participants also listened to sentences in which upcoming words could not be anticipated on the basis of WK. WK violations elicited a late negativity of greater magnitude and duration in the L2 than the L1 group. However, sentences in which WK was not helpful regarding word anticipation elicited similar N400 modulations in both groups. These results suggest that WK processing requires a deeper lexical search in L2 comprehension than in L1 comprehension.