This book constitutes the thoroughly refereed proceedings of the 4th Iberoamerican Workshop on Human-Computer Interaction, HCI-Collab 2018, held in Popayán, Colombia, in April 2018. The 18 full papers presented in this volume were carefully reviewed and selected from 83 submissions. The papers are dealing with topics such as emotional interfaces, HCI and videogames, computational thinking, collaborative systems, software engineering and ICT in education.