The authors report two studies that examined how native- and second-language skills were related to second-language reading difficulties for native Chinese-speaking fourth graders learning to read English. In study 1, 50 poor English readers with Chinese-reading difficulties (the PB group) and 34 poor English readers without Chinese-reading difficulties (the PE group) were compared with 53 typically developing controls on phonological awareness, rapid naming, and phonological memory. Results showed that both groups of poor English readers showed English phonemic awareness and rapid naming deficits in both languages and that the PB group had additional skill deficits in English onset-rime awareness and phonological memory in both languages. In study 2, 69 poor English readers (25 in the PE group) trained on English phonological skills were compared with 43 typically developing controls before the training, right after, and one year later. Results showed that poor English readers caught up with their typically developing peers on English phonemic awareness irrespective of their Chinese-reading status and that the PE group also caught up on English pseudoword reading and retained their gains one year later. After one year, about one third of the PE group performed comparably to their typically developing peers not only on English reading performance but also on bilingual language skills. However, the majority of the poor English readers persistently showed poor performance in English reading and phonemic awareness, as well as in Chinese and English rapid naming. Findings highlight both language-universal and specific skill deficits contributing to second-language reading difficulties.