BackgroundSince the WHO’s Alma Ata Declaration on Primary Health Care (PHC) there has been debate about the advisability of adopting comprehensive or selective PHC. Proponents of the latter argue that a more selective approach will enable interim gains while proponents of a comprehensive approach argue that it is needed to address the underlying causes of ill health and improve health outcomes sustainably.MethodsThis research is based on four case studies of government-funded and run PHC services in Adelaide, South Australia. Program logic models were constructed from interviews and workshops. The initial model represented relatively comprehensive service provision in 2010. Subsequent interviews in 2013 permitted the construction of a selective PHC program logic model following a series of restructuring service changes.ResultsComparison of the PHC service program logic models before and after restructuring illustrates the changes to the operating context, underlying mechanisms, service qualities, activities, activity outcomes and anticipated community health outcomes. The PHC services moved from focusing on a range of community, group and individual clinical activities to a focus on the management of people with chronic disease. Under the more comprehensive model, activities were along a continuum of promotive, preventive, rehabilitative and curative. Under the selective model, the focus moved to rehabilitative and curative with very little other activities.ConclusionThe study demonstrates the difference between selective and comprehensive approaches to PHC in a rich country setting and is useful in informing debates on PHC especially in the context of the Sustainable Development Goals.