Purpose: Identifying children with primary or specific language impairment (LI) in languages other than English continues to present a diagnostic challenge. This study examined the utility of English and Spanish nonword repetition (NWR) to identify children known to have LI. Method: Participants were 4 groups of school-age children (N = 187). There were 2 typically developing groups: proficient Spanish-English sequential bilinguals and monolingual English speakers. There were 2 groups of children with LI, one Spanish-English and the other monolingual English speakers. Children participated in both English and Spanish NWR. Results: Children's NWR performance was significantly correlated across languages. In English NWR, the 2 groups with LI had lower accuracy at the longest syllable length than the 2 typically developing groups. In Spanish NWR, monolingual children with LI had lower repetition accuracy than bilingual children with LI and typical monolingual children, with all 3 groups outperformed by the typical bilingual group. Likelihood ratios indicated adequate diagnostic power only for English NWR in ruling out the typical bilingual children as showing LI. Conclusion: The results demonstrate that NWR performance relies on the dual influences of LI and native language experience. However, it remains possible that NWR is useful in a composite marker for LI. (Contains 4 tables and 2 figures.)