This book constitutes the refereed proceedings of the 12th Colombian Conference on Computing, CCC 2017, held in Cali, Colombia, in September 2017. The 56 revised full papers presented were carefully reviewed and selected from 186 submissions. The papers are organized in topical sections on information and knowledge management, software engineering and IT architectures, educational informatics, intelligent systems and robotics, human-computer interaction, distributed systems and large-scale architectures, image processing, computer vision and multimedia, security of the information, formal methods, computational logic and theory of computation.