In Namibia, support through the Global Fund and President's Emergency Plan for AIDS Relief has facilitated an increase in access to HIV and AIDS services over the past 10 years. In collaboration with the Namibian government, these institutions have enabled the rapid scale-up of prevention, treatment and care services. Inadequate human resources capacity in the public sector was cited as a key challenge to initial scale-up; and a substantial portion of donor funding has gone towards the recruitment of new health workers. However, a recent scale-down of donor funding to the Namibian health sector has taken place, despite the country's high HIV and AIDS burden. With a specific focus on human resources, this paper examines the extent to which management processes that were adopted at scale-up have proven sustainable in the context of scale-down. Drawing on data from 43 semi-structured interviews, we argue that human resources planning and management decisions made at the onset of the country's relationship with the two institutions appear to be primarily driven by the demands of rapid scale-up and counter-productive to the sustainability of interventions.