During the Fourth Industrial Revolution, last-mile delivery underwent notable improvements due to technological applications. This research examines the key factors affecting user satisfaction and the intention to utilize smart lockers within the last-mile delivery framework in Vietnam. The research targets 345 participants residing in Vietnam, employing online surveys and in-person interviews at shopping centers, residential areas, offices, and universities over one month. The collected data is analyzed using SPSS 22.0 and SmartPLS 4.0, including assessments of measurement scales and structural model hypotheses testing. Theoretically, this research bridges gaps in existing studies by applying PMT and TAM theories to a developing country where e-commerce is rapidly expanding post-COVID-19. Practically, understanding user behavior towards smart lockers provides logistics businesses with a solid foundation for the broader implementation of these systems, thereby contributing to overall urban logistics and customer satisfaction in Vietnam. Despite its contributions, this study has certain limitations. Hence, future research should consider expanding the sample size and including participants from different geographical areas to improve generalizability.