This study examined the effects of an intervention helping struggling readers improve their reading and writing skills in English as a foreign language (L2), and those same skills in Arabic, which was their first language (L1). Transferring linguistic skills from L2 to L1 is termed "cognitive retroactive transfer". Tests were administered to the experimental and control groups that assessed orthographic knowledge, phonological awareness, morphological awareness, syntax awareness, reading accuracy, and reading comprehension in Arabic and English. The experimental group received an intervention program in English, but not in Arabic, and the assessments were administered before and after the intervention. The findings indicated a significant improvement in the experimental group's achievements in all linguistic and metalinguistic skills in both Arabic and English after the English intervention program, with the exception of orthographic knowledge in Arabic. Therefore, foreign language learning can result in improvements in native language skills. (Contains 2 tables.)