This book constitutes the refereed proceedings of the 17th Conference on Optimization and Information Systems, COSI 2025, held in Bejaïa, Algeria, during June 1–3, 2025.

The  45 papers were accepted, including 12 short papers and 33 full papers , among which 27 finally included in this volume were carefully reviewed and selected from 81 submissions.They are organized into the following topical sections: Artificial Intelligence,Operational Research and Decision Support Systems and Cybersecurity and Applications.