The major purpose of this dual-focused study was to determine the long-term effect of a maintenance bilingual education (MBE) program (K-2) on the acquisition of English (L2) and/or Spanish (L1)forfour groups of native Spanish-speaking boys and girls with varying degrees of Spanish oral proficiency who were all limited English proficient (LEP). The first part of the study examined the acquisition of English oral language proficiency forfluent Spanish-speaking boys (n = 65) and girls (n = 46), as well asfor limited-Spanish-proficient boys (n = 102) and girls (n = 85). The second part further examined the limited-Spanish-proficient subjects by gender for their acquisition of English and Spanish. These two groups were the most-limited language proficient (boys n = 45, girls n = 32) and the very-limited language proficient (boys n = 60, girls n = 53) students. The most significant overall findings emerging from this study related to the additive effects that the MBE program fostered for boys' and girls' oral English and/or Spanish.