Smartphone enables its users to download and install software, games and other programmes provided by third-party providers. The third-party software, that is installed on most Smartphones, are also known as a mobile application. These existing mobile applications run on mobile operations systems. The purpose of this study is to explain the factors affecting the user acceptance of Telegram app in Uzbekistan. In order to comprehend user acceptance of this application, it is necessary to examine the determinants of behavioral intention to use the application. Thus, this study developed a research model, based on the Unified Theory of Acceptance and Use of Technology (UTAUT). This study is aimed to identify the factors that affect the user behavior, proposing a model based on a UTAUT model. Therefore, the result is considered to be valuable in finding the other application in Uzbekistan, as this study focused on Telegram users in Uzbekistan. SPSS 22.0 was used for basic statistics and Smart PLS 2.0 was used for hypothesis testing. The empirical results of this study are summarized as follows. First, performance expectancy, effort expectancy, social influence and facilitating conditions significantly affect behavioral intention. Second, behavioral intention significantly affect use behavior.