This paper investigates the use of politeness strategies in 32 discussion sections of research papers produced by Thai graduate students at Graduate School of Language and Communication, National Institute of Development Administration (NIDA), Bangkok, Thailand. The study reported in this paper adopts Brown and Levinson's (1978, 1987) and Myers' (1989) models of politeness strategies. The project as a whole aims to identify what politeness strategies are most commonly used in the whole corpus, whether differences exist in the use of these politeness strategies and how politeness strategies are employed. The analysis of the data reveals that these student researchers rarely employed politeness strategies in their discussions. However, they used more negative politeness strategies than the positive ones and the differences in the use of these two strategies were highly significant. This study provides some pedagogical implications for ESL/EFL academic writing and syllabus designing.