The article reviews significant findings from over 15 years of research on the culture of fertility and family transitions in two Tamang communities of Nepal. The data sources include both qualitative ethnography and quantitative survey materials collected from the collaborative Tamang family research project. The major findings indicate that behavioral transitions in family and childbearing patterns are closely associated with changing economic contexts away from earlier subsistence production to increasing involvement in the monetized economy. More recently, research has further indicated the beginnings of transitions in the cultural contexts of family and identity. The authors suggest that the moral entailments of Tamang patterns of meaning are the key to variations in behavior in response to changing material conditions.