This book constitutes the refereed proceedings of the 18th Asian Conference  on Recent Challenges in Intelligent information and Database Systems , ACIIDS 2026 , held in Kaohsiung, Taiwan during April 13&15, 2026 . The 81 full papers included in this book were carefully reviewed and selected from 431 submissions. They were organized in topical sections as follows: Deep Learning Methods and Architectures; Generative, Foundation and Large Language Models; Explainable, Trustworthy and Responsible AI; Graph-Based Learning and Knowledge Systems; Image, Video and Multimedia Processing; Speech and Natural Language Processing; Optimization and Intelligent Decision Systems; Intelligent Systems for Healthcare and Bioinformatics; Federated, Distributed and Edge Intelligent Systems; Intelligent Applications in Industry, Management and Smart Infrastructure; Security, Privacy and Adversarial Learning.