Vietnam has been receiving more opportunities to develop its economy since 2007, the year of its joining the World Trade Organization. Numerous companies from other countries (e.g., American, Japanese, Korean, Singapore, and so on) have either established branches in Vietnam or poured their capital, technology, and workforce into domestic companies in an attempt to acquire great benefit from the developing market. The need for a foreign language to communicate with foreigners has significantly increased for their Vietnamese employees. Among all languages, English is considered the most popular. Consequently, it has become a prerequisite condition for working for those companies and for achieving better positions even in domestic companies. With respect to cross-cultural communication, several studies in different languages (e.g., Arabic, Australian, Japanese, and Vietnamese) were conducted to discover the mechanics of communication. The speech act of refusal was among the most focused phenomena when researchers studied cross-cultural communication since it possibly has the greatest potential for causing misunderstandings or a communication breakdown. Among the numerous researchers investigating the field, Beebe, Takahashi, and Uliss-Weltz (1990), Bardovi-Harlig and Hartford (1991), Steven (1993), Dung (1995), Chen (1996), Al-Issa (1998), Gass and Houck (1999), Phan (2001), Nguyen (2006), Wa (2009), and Tran (2011) are the those whose studies are reviewed in the present paper.