Tourism sector has been evidenced and demonstrated in a lot of academic research studies and journals that how significant its potential is for stimulating growth and promoting development. Yet, the contrary of tourism development and its negative impacts on the environment has also been raised and criticized by a number of researchers (Getz, 1983; O’Reilly, 1986; McCool & Lime, 2001). In response to this, the term sustainable tourism development has become popular worldwide for these last decades. As a developing country in Southeast Asia, the main focus of Vietnam government is to promote tourism into a ‘‘spearhead’’ economic sector with ‘‘sustainable development’’ which can create momentum for other sectors. Phu Quoc Island is one the most visited places in Vietnam. The island had almost 4 million tourist arrivals for the first nine months in 2019. Currently, a large number of large-scale projects and major high-end developments with high quality are implemented to make Phu Quoc one of the most attractive destinations in the tourism world map. Thus, the aim of this paper is to analyze the complexity of impacts that tourism development has brought to Phu Quoc and thereby consider its contributions on sustainable development of Phu Quoc in long-term perspective. In addition, this paper also seeks to address the challenges that Phu Quoc is facing whilst implementing tourism development plans towards sustainability.