In this study we investigate the linguistic performance of a school age French-Greek simultaneous bilingual boy with specific language impairment (SLI) on the production of subject-verb agreement, object clitic pronouns and wh-questions. In addition, we compare his performance on these linguistic structures with that of two French-Greek bilingual children with typical development matched on language age. Furthermore, we discuss the performance of the child with SLI in the light of published data from monolingual French and Greek school-age children with SLI, as reported in the relevant literature. The results indicated that the performance of the bilingual French-Greek-speaking child with SLI was highly comparable to that of bilingual French-Greek typically developing children and monolingual children with SLI speaking French or Greek. In addition, the results revealed a language effect on the performance of the bilingual child with SLI on subject-verb agreement, object clitics and wh-questions. We adopt a comparative linguistic approach to interpret the results and argue that the specific linguistic properties of Greek and French were significant determinants for the manifestation of SLI in each language. We suggest that bilingualism per se did not aggravate the language deficits in this child with SLI. Finally, we discuss the clinical implications of our study for language intervention in bilingual individuals with SLI. (Contains 19 notes and 12 tables.)