This article reviews a program of research on how groups reason about moral dilemmas, and presents data from two studies. In the first study, discussions of 21 four-member groups were tape recorded, coded, and analyzed to identify the factors that affected group performance. The data indicated that a group's moral reasoning level (as measured by Rest's Defining Issues Test) seemed to depend on whether more principled reasoning members took a task leadership role. The second study attempted to manipulate the leadership variable by assigning the task leadership role to individuals who reasoned at more vs. less principled levels. Results indicated that the reasoning level of the assigned leader impacted group performance while individual performance overall on a subsequent moral reasoning task benefitted from the group experience. The extent of the individual change was influenced by subjects' initial reasoning level. Implications for management are discussed.