The role of social workers within the Hong Kong psychiatric service is not satisfactory. This paper argues that these roles should be flexibly re-examined and revised, so that the needs of the mentally ill patients and their families and new challenges faced by the mental health service can be met. To enhance service quality, social workers employed in a psychiatric setting need to improve their manpower ratio, gain professional knowledge, be involved in clinical supervision, coordinate teamwork, assume an active role in policy change and advocacy, and engage in empirically based research.