This study examined whether, and if so how, L1 and L2 segmental and suprasegmental phonological awareness is longitudinally related to L1 and L2 reading comprehension difficulties among Hong Kong Chinese-English bilingual children. Using a regression approach, we identified five types of comprehenders, i.e., 11 poor-Chinese/average-English comprehenders, 19 poor-English/average-Chinese comprehenders, six poor-Chinese/poor-English comprehenders, 12 average-Chinese/average-English comprehenders, and seven good-Chinese/good-English comprehenders among 223 Grade 4 Chinese-English bilingual children who were comparable in age, nonverbal IQ, and word reading, but differed in reading comprehension. These children were compared retrospectively on segmental and suprasegmental phonological awareness in both Chinese and English for three consecutive years from Grade 2 to Grade 4. The results revealed that only Cantonese lexical tone awareness distinguished poor comprehenders from typically developing comprehenders. Specifically, the poor-English/average-Chinese comprehenders performed worse than the average-Chinese/average-English and good-Chinese/good-English comprehenders in Grades 4 and 3, but not in Grade 2; and the poor-Chinese/average-English comprehenders performed worse than the good-Chinese/good-English comprehenders in Grades 4 and 3, but not in Grade 2. These findings suggest that suprasegmental phonological awareness, especially Cantonese lexical tone awareness, is critical for both Chinese and English reading comprehension development among Hong Kong bilingual children.