This book constitutes the refereed proceedings of the 6th EAI International Conference on Cognitive Computing and Cyber Physical Systems, IC4S 2025, held in Andhra Pradesh, India, during December 15-17, 2025.The 27 full papers included in this book were carefully reviewed and selected from 110 submissions. They were categorized under the topical sections as follows: Signal Processing; Medical Diagnostics and Healthcare; AI-Enabled Technologies; AI and IoT Advance Applications; Computing Techniques; and Applications of Cyber-Physical Systems.