International payment is an essential part of the economy, which is beneficial to both commercial banks and trading enterprises. Moreover, service quality, which has been a key point of discussion for decades, relates to customer satisfaction. This study aims to investigate the factors influencing international payment service quality at the Join Stock Commercial Bank for Investment and Development of Vietnam (BIDV) from 2015 through 2019. This research deploys both quantitative and qualitative methods to discuss the effects of these components. Statistical data was examined through different tests, including reliability analysis, correlation, and regression analysis by SPSS 16.0. The authors obtain and analyze 157 valid responses from customer surveys, then by applying an integration SERVPERF and PSQM model, identify five main components: Reliability, Tangibles, Assurance, Convenience, and Responsiveness, which explain how the customer perceives the service quality of international payment activities at BIDV. The results show that these five factors have a positive relationship with service quality, in which, Reliability has the most significant impacts on service quality level. Besides, the findings not only contribute to the literature but also give some practical implications for BIDV to improve its international payment service quality and help them to obtain customer satisfaction in the fast-changing environment.