A growing corpus of evidence suggests that morphology could play a role in reading acquisition, and that young readers could be sensitive to the morphemic structure of written words. In the present experiment, we examined whether and when morphological information is activated in word recognition. French fourth graders made visual lexical decisions to derived words preceded by primes sharing either a morphological or an orthographic relationship with the target. Results showed significant and equivalent facilitation priming effects in cases of morphologically and orthographically related primes at the shortest prime duration, and a significant facilitation priming effect in the case of only morphologically related primes at the longer prime duration. Thus, these results strongly suggest that a morphological level is involved in children's visual word recognition, although it is not distinct from the formal one at an early stage of word processing.