This book constitutes the refereed proceedings of the 17th International Conference on Group Decision and Negotiation, GDN 2017, held in Stuttgart, Germany, in August 2017. The field of Group Decision and Negotiation focuses on decision processes with at least two participants and a common goal but conflicting individual goals. Research areas of Group Decision and Negotiation include electronic negotiations, experiments, the role of emotions in group decision and negotiations, preference elicitation and decision support for group decisions and negotiations, and conflict resolution principles. The 14 full papers presented in this volume were carefully reviewed and selected from 87 submissions. They were organized in topical sections named: general topics in group decision and negotiation; conflict resolution; emotions in group decision and negotiation; negotiation support systems and studies; and preference modeling for group decision and negotiation. The book also contains two invited talks in full paper length.