This study investigates the effects of disparate L1 (first language) alphabetic experience on L2 (second language) phonemic awareness and decoding among ESL (English as a Second Language) readers with alphabetic and nonalphabetic L1 orthographic backgrounds. It was hypothesized that amount of L1 alphabetic experience is causally related to the development of L2 phonemic awareness and decoding skills. The specific objectives were threefold: to compare varying aspects of phonemic awareness among Chinese and Korean ESL learners; to explore the relationship between L2 phonemic awareness and decoding skills;and to examine the extent to which L2 text comprehension is facilitated by phonemic awareness and decoding skills. Data demonstrated that the two groups differed neither in their phonemic awareness nor in decoding;phonemic awareness was differentially related to decoding performance between the groups; and strong interconnections existed between reading comprehension, decoding and phonemic awareness among Korean participants, but no such direct relationships occurred among Chinese. Viewed collectively, these findings seem to suggest that, while differential L1 orthographic experience is not directly associated with L2 phonemic awareness, variations in prior processing experience may engender the use of diverse phonological processing procedures and, thus, account for qualitative differences in L2 processing behaviours.