This research examined understandings of cultural competence of social workers in Hong Kong, their needs and challenges in serving culturally diverse groups, and their willingness and receptivity to receive cultural competence training by using constructivist grounded theory. Individual qualitative interviews were conducted with thirteen frontline and managerial practitioners and educators in training institutions in the social work profession. Data were analysed by identifying major themes. The findings show that social workers in Hong Kong tend to encounter language barriers and various forms of cultural shocks in serving ethnoculturally diverse clients. The professional code of practice is not sufficient in promoting culturally competent practice and there are institutional barriers to the enhancement of cultural competence of the social services. Mainstream social work units are generally not well prepared to provide services to non-Chinese communities. In response to these obstacles, professional training should provide future Hong Kong social workers with opportunities to interact with ethnoculturally diverse communities through service-learning. To tackle institutional racism, leaders should have cultural awareness and promote culturally inclusive practices. Inclusion of staff members from diverse cultural backgrounds would increase the capacity of the organisations to better serve clients of diverse needs. Anti-racism training should be made as an essential professional development component for social work students, practicum students, practitioners and managers.