Cognitive neuropsychological studies of bilingual patients with aphasia have contributed to our understanding of how the brain processes different languages. The question we asked is whether differences in script have any impact on language processing in bilingual aphasic patients who speak languages with different writing systems: Chinese and Mongolian. We observed a pattern of greater impairment to written word comprehension and oral reading in L2 (Chinese) than in L1 (Mongolian) for two patients. We argue that differences in script have only a minimal effect on written word processing in bilingual aphasia when the age of acquisition, word frequency and imageability of lexical items is controlled. Our conclusion is that reading of familiar words in Mongolian and Chinese might not require independent cognitive systems or brain regions. (Contains 1 footnote.) [This work was also supported by the Research Grants Council of the Hong Kong Government.]