An implicit word learning paradigm was designed to test the hypothesis that children who came to the task of L2 vocabulary acquisition with poorer L1 phonological awareness (PA) are less capable of extracting phonological patterns from L2 and thus have difficulties capitalizing on this knowledge to support L2 vocabulary learning. A group of Chinese-speaking six-grade students took a multi-trial L2 (English) word learning task after being exposed to a set of familiar words that rhymed with the target words. Children's PA was measured at grade 3. Children with relatively poorer L1 PA and those with better L1 PA did not differ in identifying the forms of the new words. However, children with poorer L1 PA demonstrated reduced performance in naming pictures with labels that rhymed with the pre-exposure words than with labels that did not rhyme with the pre-exposure words. Children with better L1 PA were not affected by the recurring rime shared by the pre-exposure words and the target words. These findings suggest that poor L1 PA may impede L2 word learning via difficulty in abstracting phonological patterns away from L2 input to scaffold word learning.