In this paper, I am going to look at the issues of TESOL from one major critical point of view: How the use of the Internet technology might influence TESOL syllabus design and materials development. The article attempts to investigate some possibilities and opportunities provided by the Internet, focusing on the World Wide Web (WWW) as credible ways to access up-to-date and authentic language resources and materials for language teachers and learners of a foreign language. Besides, some challenges caused by the application of the new technology into language education for Vietnamese syllabus designers are addressed. Accordingly, the Vietnamese context is tentatively kept in view throughout these discussions. It is argued that technology can enhance the quality of syllabus design and material development, and that though the focus of problems and challenges is on the particular Vietnamese social setting, there is no reason in which the concerns considered cannot be shared in other relevant milieu.