Jewish social workers work in agencies sponsored, directed and financed by Jews. Agency boards are (or should be) representative of the Jewish communities in which the agencies operate. There is no general agreement on the nature of the Jewish community in the United States, but we know that it is composed of many elements, that it is subject to influences of diverse ideologies, and that structurally it expresses itself through a variety of organizational forms. In many ways the pattern of Jewish community life differs from that of the general community. Social workers need to be familiar with that pattern. Their work with individuals and groups will be more effective and more productive if it is based on knowledge of the historical and contemporary factors that enter into the organization of the Jewish community, and on an appreciation of the interplay of group forces and ideologies.