For over two decades, the Office of the UN High Commissioner for Human Rights (OHCHR) has taken a leading role in promoting human rights globally by building the capacity of people to claim their rights and governments to fulfill their obligations. This chapter examines the extent to which the right to health has evolved in the work of the OHCHR since 1994, drawing on archival records of OHCHR publications and initiatives, as well as interviews with OHCHR staff and external experts on the right to health. Analyzing this history, the chapter then points to factors that have facilitated or inhibited the mainstreaming of the right to health within the OHCHR, including (1) an increasing acceptance of economic and social rights as real human rights, (2) right-to-health champions among the leadership, (3) limited capacity and resources, and (4) challenges in moving beyond conceptualization to implementation of the right to health.