This research was undertaken to explore the potential application of Human Resource (HR) Business Process Outsourcing (BPO) as an appropriate service delivery mechanism. The investigation included the identification of the primary internal drivers and external factors affecting HR departments, to craft the framework within which to consider HR BPO. Then the processes that could be delivered by HR BPO were identified. The study concluded with the identification of the critical success factors for implementing HR BPO and the expected benefits. The research was conducted by means of 26 in-depth, semi-structured interviews with senior HR managers and HR professionals. The respondents represented various industries and sectors and included leading South African organisations and a range of global organisations. The resulting findings first introduce the bridge principle, to ensure that HR transformation is not at the expense of line management. Secondly a decision model, which incorporates benefit realisation principles, was developed to assess the applicability of HR BPO for processes. The findings conclude with a success factor condition table that highlights the critical success factors and their dependencies.