Purpose: Given the complexity of sentence processing and the specific problems that children with specific language impairment (SLI) experience, we investigated the time course and characteristics of semantic processing at the sentence level in Dutch preschoolers with SLI. Method: We measured N400 responses to semantically congruent and incongruent spoken sentences (e.g., "My father is eating an apple/*blanket") in a group of 37 Dutch preschoolers with SLI and in a group of 25 typically developing (TD) peers. We compared the time course and amplitude of the N400 effect between the two groups. Results: The TD group showed a strong posterior N400 effect in time windows 300-500 ms and 500-800 ms. In contrast, the SLI group demonstrated only a reliable N400 effect in the later time window, 500-800 ms, and did not show a stronger presence at posterior electrodes. Conclusion: The findings suggest that the neuronal processing of semantic information at sentence level is atypical in preschoolers with SLI compared with TD children.