Vulnerability’ is now a popular term in the lexicon of every-day life and a notion frequently drawn upon by policy-makers, academics, journalists, welfare workers and local authorities. This essay explores some of the ethical and practical implications of ‘vulnerability’ as a concept in social welfare. It highlights how ideas about vulnerability shape the ways in which we manage and classify people, justify state intervention in citizens’ lives, allocate resources in society and define our social obligations. The lack of clarity and limited analysis of the concept of ‘vulnerability’ in welfare arenas is highlighted as concerning, particularly given that those seen as most in need of support seem to be implicated in commonly held views about ‘the vulnerable’. I argue that far from being innocuous, ‘vulnerability’ is so loaded with political, moral and practical implications that it is potentially damaging to the pursuit of social justice. Two opposing presentations of the notion are set out in order to illustrate that ‘vulnerability’ is a concept that should be handled with more care.