Outsourcing is a complex, controversial and pervasive practice that is increasingly becoming a matter of concern for educational researchers. This article contributes to this literature by examining outsourcing practices related to health, sport and physical education (HSPE). Specifically, it reports data on specialist health and physical education (HPE) teachers', principals' and external providers' reasons for participating in outsourcing arrangements. These data were obtained from a collective case study of six schools and the external providers that they outsourced HSPE to over a 12-month period, using semi-structured interviews and overt participant observations. The findings illustrate the ways in which the informants explained their outsourcing practices using a variety of educationally and organisationally oriented reasons. Educational value, human resources (e.g. expertise), physical resources (e.g. facilities) and symbolic resources (e.g. status) were reasons for outsourcing HSPE that were commonly cited by principals and specialist HPE teachers. Among external providers, educational value, income generation and promotion/advertising were frequently cited to explain their work with and for schools. These findings illustrate the ways in which outsourcing practices in HSPE articulate with, and are implicated in, broader educational privatisations. They also highlight the boundaries that outsourcing practices trouble or reinforce, such as those marking the purview of markets, membership of the HPE profession and the constitution of expertise.