Today's twenty-first-century library and information science (LIS) professionals are faced with the challenge of a growing population of individuals from diverse cultural backgrounds, many of whom are from minority and underserved populations representing the poorest segments of society with little or no experience with libraries. This article argues that although considerable efforts have been made by LIS professionals to meet the needs of minorities and underserved populations, a cultural competence framework is needed for these efforts to be successful. This article proposes a conceptual framework for developing cultural competence for LIS professionals and identifies three domains in which cultural competence is developed: cognitive, interpersonal, and environmental. The development of cultural competence within these domains is discussed, and essential elements needed to develop cultural competence within the domains are identified.