This volume contains the papers presented at the 28th International Conference on Collaboration Technologies and Social Computing (CollabTech 2022). The conference was held during November 8-11, 2022, in Santiago, Chile, in hybrid format. This year we received 38 submissions, including 26 full papers and 11 work in progress (WIP) contributions. Each paper was carefully reviewed by three to five Program Committee members in a double-blind process. As a result, the committee decided to accept 18 full and 4 WIP papers. The accepted papers present relevant and interesting research works related to theory, models, design principles, methodologies, and case studies that contribute to a better understanding of the complex interrelations that exist at the intersection of collaboration and technology. The program also included two keynote presentations. As editors, we would like to thank the authors of all submissions and the members of the Program Committee for their careful reviews. Our thanks also go to the Universidad de los Andes, Chile, and its Faculty of Engineering and Applied Sciences, for hosting and supporting the conference through the "Fondo de Ayuda a la Investigación" (FAI) program. We thank the Universidad de Chile, including the Department of Management Control and Information Systems and the Department of Computer Science, for their support. Our special thanks go to the Information Processing Society of Japan (IPSJ) for their sponsorship. Finally, we would like to acknowledge the effort of the organizers of the conference, as well as thank the Steering Committee for the opportunity to organize the conference and their help provided in the process.