This book constitutes the refereed post-conference proceedings of the 12th EAI International Conference on Mobile Networks and Management, MONAMI 2022, which took place virtually during October 29-31, 2022. The 31 full papers were carefully reviewed and selected from 78 submissions. The papers are divided into groups of content as follows: Innovative Artificial Intelligence Applications for Smart City; The New Era of Computer Network by using Machine Learning; Advanced Technologies in Edge and Fog Computing; Emerging Technologies in Mobile Networks and Management; and Recent Advances in Communications and Computing.