This study aims to compare and contrast Thai and English narrative essays written by six Thai-English bilinguals to determine if there is any change in the textual coherence between L1 and L2 writings. Participants were asked to compose English and Thai narrative essays using a picture cue. The subjects wrote first in English and later in Thai with a three-week interval between writing sessions. The research focuses on aspects of syntactical structure as well as narrative discourse structures of L1 and L2 narrative essays created by male and female Thai advanced English writers. The results reveal that in terms of textual cohesion, Thai-English bilinguals prefer using anaphoric references to cataphoric references and incorporating more nominal and comparative pronouns in English than in their Thai writings. However, the subjects utilized a larger number of demonstrative pronouns in Thai writings than in English because of the lack of the definite article the in the Thai language. The infrequent use of substitution and ellipsis in both L1 and L2 sample writings lead the researcher to postulate that the subjects lack knowledge of such features. Thai bilinguals were also found to be more proficient in connecting their L1 Thai writings by using conjunctions than in their L2 English narrative essays. The subjects used the same lexicons to create the textual coherence in both their Thai and English writings. Based on the narrative discourse findings of the study, the researcher has postulated that lexical replacements in the subjects' L1 and L2 writings were caused by their limited lexical storage and personal experience. Furthermore, it appears that societal influences such as family background, social value, and religion are reflected in the content and morality of narrative essays created by Thai-English bilinguals. Finally, it appears that limited exposure to writing instruction has resulted in the deficient use of dialogue, narrator in narrative writing, figurative language, and titles of narrative writings in both Thai and English writings. (Dissertation Abstracts)