A comprehensive primary health care approach is required to address complex health issues and reduce inequities. However, there has been limited uptake of this approach by health services nationally or internationally. Reorienting health services towards becoming more health promoting provides a mechanism to support the delivery of comprehensive primary health care. The aim of this study was to determine the impact of a health promotion-focused organisational development strategy on the capacity of a primary health care service to deliver comprehensive primary health care. A questionnaire and semistructured individual interviews were used to collect quantitative and qualitative impact evaluation data, respectively, from 13 health service staff across three time points with regard to 37 indicators of organisational capacity. There were significant increases in mean scores for 31 indicators, with effect sizes ranging from moderate to nearly perfect. A range of key enablers and barriers to support the delivery of comprehensive primary health care was identified. In conclusion, an organisational development strategy to reorient health services towards becoming more health promoting may increase the capacity to deliver comprehensive primary health care.