This chapter is about the relationship between needs and rights, and what that means for social work practice. Social workers can be regarded as professional need definers. They are constantly in the process of identifying, and then trying to meet, human needs, as described back in 1945 by Charlotte Towle (Towle 1965). Scarcely a day would pass in any social worker's life when the word ‘need’ is not used on dozens of occasions. Social workers do ‘needs assessments’, talk about the needs of individuals, of families, of client groups (e.g. the aged), of communities, of agencies, of service delivery systems (e.g. the health care system) and of the whole society (e.g. the need for a better income security system). Social workers talk about ‘unmet need’, ‘needing more resources’, ‘doing a needs survey’, ‘needing more social workers’, ‘needing supervision’, and so on. ‘Need’ is one of the most commonly used words in the social work vocabulary, and it is significant that more often than not it is used, in the words of Noel and Rita Timms, ‘in the absence of any deep sense of puzzlement about the concept’ (Timms & Timms 1977: 141). Need, however, is a complex issue and requires a good deal more examination than is common in the social work literature. This book seeks to frame social work as a human rights profession rather than a human needs profession.