This 3-volume set constitutes the proceedings of 18th International Conference on Multi-disciplinary Trends in Artificial Intelligence, MIWAI 2025, held in Ho Chi Minh City, Vietnam, during December 3–5, 2025. The 110 full papers presented in these proceedings were carefully reviewed and selected from 306 submissions. The papers focus on various topics in AI and its applications, such as deep learning, machine learning, computer vision, pattern recognition, and natural language processing.