Trends toward later and less marriage and childbearing in East Asia have been even more pronounced than in the West. At the same time, many other features of East Asian families have changed very little. We review recent research on trends in a wide range of family behaviors in China, Japan, Korea, and Taiwan. We also draw upon a range of theoretical frameworks to argue that trends in marriage and fertility reflect tension between rapid social and economic change and limited change in family expectations and obligations. We discuss how this tension may be contributing to growing socioeconomic differences in patterns of family formation. This focus on East Asia extends research on the second demographic transition in the West by describing how rapid decline in marriage and fertility rates can occur in the absence of major changes in family attitudes or rising individualism.