This journal issue commemorates the recent 100th anniversary of the birth of Kurt Lewin, a founder of the Society for the Psychological Study of Social Issues and of this, SPSSI's journal. It appears that his influence in academic social psychology has declined of late, but a review of recent literature reveals that Lewin's thought and work still guide activity in applied social psychology, particularly studies of groups, and in the practice of action research. The articles in this issue further demonstrate that contemporary social scientists find stimulation and direction for theory, research, and action in Lewin's legacy.