The rapid development of telecommunication and Internet services enables smartphone users to access online services faster and create more demand for using high-speed data services. The third generation (3G) mobile services have become the pioneer for the trend of high speed data transmission for years. This study aims to explore the factors that affect behavioral intention of adopting 3G mobile telecommunications. After implementing a structural equation modeling to analyze the data collection of 223 self-administered correspondents, we found that perceived factors, including ease of use, usefulness and enjoyment have a significantly positive relationship with attitude and while the attitude is positively associated with behavioral intention to use 3G. Based on the results, the research enables us to propose several practical recommendations to 3G providers in Vietnam such as 3G providers should provide more interesting and entertaining contents in their 3G applications and services, which charge appropriate fees and are easy to use for customers. In addition, 3G providers should focus on customers' attitude by listening and receiving customers' feedbacks to improve 3G technological solutions and value-added services.