This study examined to what extent young second language (L2) learners showed morphological family size effects in L2 word recognition and whether the effects were grade-level related. Turkish-Dutch bilingual children (L2) and Dutch (first language, L1) children from second, fourth, and sixth grade performed a Dutch lexical decision task on words with varying family sizes. The responses of both L1 and L2 children were more accurate (in second grade) and faster (in fourth and sixth grades) for words with a large family than for words with a small family, even though the L2 children had a smaller vocabulary size in Dutch than the L1 children. These findings show how the spreading of semantic activation across languages can influence word recognition in L2 learners.