Writing effectively in an academic setting is a challenge for many students, especially at the graduate level. Graduate students often struggle with the demands of writing a thesis, which is a specific genre of writing with its own set of standards, norms and conventions. The difficulties described above deepen for students who have to write in their second language. Since language and writing are culture specific, each language has its own unique rhetorical conventions. By comparing three different theses, this study aims to identify the differences between Thai and English discourse. Understanding these differences will provide some guidance to Thai students who are writing their theses in English.