This three-volume set CCIS 2943-2945 constitutes the refereed proceedings of the Second International Conference on Computational Intelligence in Engineering Science, ICCIES 2026, held in Nha Trang, Vietnam, during April 2&4, 2026. The 131 full papers included in these volumes were carefully reviewed and selected from 290 submissions. They were organized into topical sections as follows: Part I: Natural Language Processing; Computer Vision Part II: Machine Learning; Intelligent Systems; IoT Part III: Wireless Networks (6G); Cyber Security; Control System.