What are the longitudinal cognitive profiles of Hong Kong Chinese children with specific reading difficulties in Chinese only, in English only, or both? A total of 16 poor readers each of Chinese (PC) and English (PE) and 8 poor readers of both orthographies (PB) were compared to a control sample (C) of 16 children; all were drawn from a statistically representative sample of 154 Hong Kong Chinese children tested at ages 5 to 9 years. PE and PB children’s mothers had lower education levels than did the other groups. With children’s ages and mothers’ education levels statistically controlled, the PE, PC, and PB groups were significantly lower than the C group on phonological awareness. The PB and PE groups also scored significantly lower than the others on English vocabulary across years, whereas the PC and PB groups were significantly poorer than the C and PE groups on morphological awareness across years. Finally, the PB group was significantly slower than the other groups on speed naming at every age tested, underscoring the potential importance of automaticity in reading across orthographies. Findings highlight the need to consider the issue of how to identify reading difficulties in a second language.