This article analyses the diversity of public organizations focusing on variations in their degree of publicness. We define ‘publicness’ as organizational attachment to public sector values: for example, due process, accountability, and welfare provision. Based on a survey of Danish public organizations, we show that organizations with a high degree of publicness differ from organizations with a low degree of publicness. The former are characterized by complex tasks, professional orientation, many external stakeholders, conflicting environmental demands, and low managerial autonomy. The latter are the opposite. We explore in detail both the relationship between the organizations and their parent ministries and their responses to organizational change. Organizations with a high degree of publicness are subject to a tight ministerial control and have formal and distant relations with the ministry. They also have strong vertical links, externally and internally. High internal control is the joint product of ministerial control and the stress on the public sector value of rule compliance. All organizations ranked high on publicness are reluctant to adopt organizational changes stemming from the ‘New Public Management’. Again, organizations with a low degree of publicness are the opposite, keen to adopt new ideas. We show that degree of publicness matters, across both functional types of organizations and policy sectors. Finally, we discuss alternative theoretical explanations of publicness drawn from contingency theory and the new institutionalism.