The CCIS book constitutes selected papers of the 12th International Conference on Computational Science and Computational Intelligence, CSCI 2025, which took place in Las Vegas, NV, USA, during December 3–5, 2025.

The 38 full papers and 4 poster papers included in this book were carefully reviewed and selected from a total of 389 submissions to the Research Track on Artificial Intelligence, CSCI-RTAI. They were organized in topical sections as follows: Learning Strategies - Transfer Learning and Reinforcement Learning; Artificial Intelligence - Applications of Graphs and Networks; Artificial Intelligence - Natural Language Processing & Large Language Models; Artificial Intelligence - Prediction and Forecasting Methods; Artificial Intelligence - Algorithms and Applications; and Poster Papers.