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.