Important decisions are often taken by groups of decision-makers who need to choose among several alternatives in view of multiple objectives, in recognition of the interests of stakeholders. Such decision problems can be supported with the methods and processes of multicriteria decision analysis (MCDA) which foster collaboration, lend structure to the decision process, and help in managing problem complexity. In this chapter, we examine rationales for using MCDA methods in group decision processes, outline typical phases of these processes, summarize widely used MCDA methods and discuss some of their recent methodological extensions. We also provide guidelines for the design and implementation of MCDA-assisted group decision processes, based on an examination of behavioral factors and a structured review of selected case studies. We conclude with an outlook for the future in light of recent developments and trends.