Abstract—English has been a lingua franca in various domains of communication such as international
business, academic conferences, diplomacy, science and technology. As a result, the demands for English skills
in all aspects are crucial in response to the importance of English and the impact of globalization. Despite the
constant efforts in developing English education in Thailand, a number of studies have shown that the
achievement of Thai learners was unsatisfactory. Given the role of English as an international language which
is used in almost domain of communication, amongst several factors hindering the success of English language
learning, English pronunciation of the Thai learners should be focused. This study has two principle objectives:
1) to examine Thai learners’ knowledge with regard to word stress assignment; and 2) to determine possible
factors affecting the Thai learners’ pronunciation competence. To achieve these objectives, 90 Thai learners of
English participated in this study. The test consisting of two parts: personal information profile, and 40
selected words systematically taken from two textbooks, was employed to identify these participants’
pronunciation competence. The results showed that most of the participants’ English pronunciation was
somewhat limited. Gender was identified to be the most significant factor contributing to the participants’ test
scores, while faculty and years of studying English were not. In light of the results suggested by the three
variables, pedagogical suggestions were offered to help improve teaching and learning English pronunciation
in general, and in focusing on the importance of teaching word stress in particular.