The study examines the relationship between perceived mental benefits, online trust, and personal information disclosure when shopping online in Vietnam. The e-commerce market has been booming in Vietnam since 2015. The number of online transactions and e-commerce sites has increased steadily in recent years. However, the number of online sales in Vietnam is still not high, and consumers are still limited in buying from websites when they have to provide too much information during and after the shopping process. The mix-method is used to ensure the scientific nature of the study. Qualitative research method (phenomenological research) along with the quantitative research method (survey) are applied to meet the research objectives. The data in the study was collected through the group discussion with eight experts and the survey with 917 respondents. Data processing result via SmartPLS software indicate the positive relationships between the factors in the research. The perceived mental benefits have the most potent influence on the online trust of Vietnamese customers; at the same time, both the perceived mental benefits and online trust affect customers personal information disclosure in electronic commerce. Some managerial implications relating increasing the perceived mental benefits, and customers' online trust are proposed for online businesses.