The present study investigated the co-occurrence of word reading and spelling difficulties for Chinese first language (L1) and English second language (L2) and the role of morphological awareness in word reading and spelling ability across two languages. A total of 110 Hong Kong Chinese-speaking students in Grade 7, including 55 adolescents with dyslexia (28 males, mean age = 152.11 months) and 55 typically developing adolescents (27 males, mean age = 151.85 months) participated. They were assessed on the cognitive-linguistic measures of morphological awareness, phonological awareness, vocabulary knowledge, rapid naming, word reading, and word spelling in L1 and L2. Multivariate analysis of variance showed that compared with the typical students, adolescents with dyslexia had poorer performance in all L1 and L2 measures except the phonological awareness in Chinese. Hierarchical regression analysis indicated that for both groups of students, morphological awareness contributed uniquely to word reading and spelling in L1 and L2; rapid letter naming contributed uniquely to English word spelling. Findings highlight the importance of co-occurring difficulties in L1 and L2 reading and spelling and that morphological awareness may play a critical role in predicting word reading and spelling across languages for Chinese adolescents with dyslexia and those without difficulty. Copyright © Sage Publications Ltd.