This research is conducted on purpose to propose a personal viewpoint which answers to the question “What makes Viettel successful in international markets?” The second data as published articles and previous researches that related to the thesis topic were employed, along with the primary data as information generated from an interview with a Viettel staff, are employed to support to the observing methodology to analyze the materials. First and foremost, the study provides a general picture of each target country‟s economy as well as its telecommunication market situation, which implies either the obstacles or the favorable conditions to Viettel. Next, the marketing mix strategy that Viettel applied in these markets will be briefly recalled. After that, based on the previous information, the author will draw out factors that brought about Viettel‟s success in its foreign markets.