This longitudinal quantitative study examines the first and second language vocabulary development of prekindergarten students enrolled in an inclusive foreign language exploratory (FLEX) program. The FLEX program, framed by the Cognitive Retroactive Hypothesis of cross-linguistic transfer, is situated in a context where students with special needs are fully included in all academic activities. Data were collected over 2 years from 60 students in the form of standardized tests and classroom tests of first and second language vocabulary. Results indicate that all students showed evidence of learning second language vocabulary, although students with special needs scored lower than their peers. Furthermore, all participants showed evidence of first language vocabulary increases contradicting assumptions that foreign language exposure may cause interference with the first language for special needs students. Implications include discussion of the least restrictive environment for students with special needs by questioning deficiency-centered decisions about foreign language exemptions.