Beyond the role of the state and private sector, the task of responding to increasingly complex challenges in delivering urban health care in the early 21 st century is being met by the voluntary sector. This chapter outlines some of the key critical points of debate concerning how the voluntary sector has moved into this focal position. The first half of the chapter traces how the role of the voluntary sector has followed a complex trajectory since being 'rediscovered' by the state in the 1970s, defined by three phases: as panacea, paradox and precarity. The second part of this chapter explores how the voluntary sector is both 'in' and 'of' cities: voluntary organisations concentrate there, but they have also cultivated greater cultural proximity and solidarity with urban residents' local values. Yet, relying on a sector that by default is more de-centralised and organic becomes a challenge in contexts where urban space is marked by various pressures around precarity of health services. for people with mental health issues (DeVerteuil 2015), disabilities (Power and Bartlett 2015), and support needs in older age (Milligan and Wiles 2010). Fundamentally, the health 'system' should be understood as more than solely 'health services': it can include urban transport, community networks, public amenities, and educational services. Indeed, any community-led resource that helps people's health and wellbeing can be included. Taken together, the actions of the voluntary sector and volunteers, both formal and informal, are rooted in the broader philosophy of voluntarism-that is, non-coerced action by civil society, usually for public benefit, outside the constraints of the state (Brandsen et al 2005). When seen in this light, the voluntary sector is a significant player in urban health, through a myriad of different initiatives, for example, community transport schemes, urban farms, and lifelong learning groups (e.g. Men's Sheds). Rather than solely offer a review of literature, the purpose of this chapter is to outline some of the key critical points of debate concerning how the voluntary sector is evolving and responding to the increasingly complex challenges in delivering urban health care in the early 21 st century, drawing on pertinent literature where relevant. It is a chapter of two halves. The