This study investigates and identifies the variables that influence customers' decisions while selecting logistics service providers. 249 managers and workers from import-export companies and logistics service providers participated in a survey that generated the data. The theoretical model was tested in this study using both qualitative and quantitative approaches. The findings showed that, in addition to cost, flexibility, and information sharing, on-time delivery had the greatest beneficial influence on customers' decisions. This study also discovered that customers' decisions were unaffected by trust. Lastly, the management implications of this study were put forth in an effort to improve the performance of marine logistics service providers. Citation this article (Huỳnh et al., 2024) Huỳnh, T. N., Đinh, M. A., & Nguyễn, H. H. (2024). FACTORS AFFECTING SHIPPER’S DECISIONS ON CHOOSING SEA LOGISTICS SERVICE PROVIDER. Hoa Sen University Journal of Science, 05, 1–19. https://vjol.info.vn/index.php/dhs/article/view/104818