The Australian alcohol and other drugs (AOD) sector has a diverse range of actors, including the nongovernment (NGO) service providers. Representing these services in each of Australian states and territories are AOD sector peak bodies. Their national network commissioned an evaluation of their capacity building (CB) activities and outcomes. The network and the evaluator developed a working definition of CB: Capacity building is a strategy that improves the ability of AOD workers, services and/or the broader AOD system to achieve better AOD health and social outcomes. The utilisation-focused evaluation (UFE) model was adopted for this project. The evaluation found that sound outcomes have been produced by the peaks’ CB work, and that includes valued changes in the service delivery work of the NGO sector. The CB strategies that are particularly important for attaining the desired outcomes were identified. The CB strategies and activities have been implemented well, and have delivered value for money, though sustainability remains a concern. The evaluation concluded that the peak bodies are ideally placed to deliver CB initiatives. The evaluation’s recommendations have been implemented, and process utilisation of the evaluation has been observed among its participants.