Teamwork has been at the core of human accomplishment across the millennia, and it was a focus of social psychological inquiry on small group behavior for nearly half a century. However, as organizations world-wide reorganized work around teams over the past two decades, the nature of teamwork and factors influencing it became a central focus of research in organizational psychology and management. In this article, I reflect on the impetus, strategy, key features, and scientific contribution of “Enhancing the Effectiveness of Work Groups and Teams,” by Kozlowski and Ilgen, a review monograph published in Psychological Science in the Public Interest in 2006.