Public health agencies at all levels have struggled to identify the optimum structure to support administrative and programmatic efficiencies that will maximize public health impact with the available resources. Although public health effectiveness literature documents how a state health department should function to achieve the intended impact on population health, little is known about how organizational structure changes actually affect function, and ultimately, population health. Focusing on the chronic disease unit of a state health department, this case study examined attributes (how an organization is structured) and practices (how an organization operates). Methods for this case study included document review and key informant interviews of health department staff and external stakeholders. Data analysis suggests that the relationship between attributes and practices is complex and that organizational structure may influence not just practice but also other attributes such as goal ambiguity and workforce competency. Although the correlation analysis did not show a significant association between effectiveness and any of the elements in the conceptual model, qualitative responses indicate a belief that evidence-based decision-making, goal ambiguity, political support, responsiveness, and workforce competency all facilitate effectiveness, and that collaboration plays a fundamental role in contributing to each of those elements. Structure was identified as an influence on collaboration, responsiveness, goal ambiguity, and hierarchical authority. However, the roles of three other elements -- culture, leadership, and physical proximity - were less clear, and either mitigated the effects of structure, enhanced the effects of structure, or were amplified by structure. This study has served both to document a point in time for Montana's Bureau of Chronic Disease Prevention and Health Promotion and to explore the elements of the conceptual model that may facilitate effectiveness for chronic disease units in other states, other units in within state health departments, and public health agencies at other levels. The results of the qualitative and quantitative analysis suggest interrelationships between the elements of the model rather than a simple linear cause and effect pathway. These findings identify levers around which capacity can be built that may strengthen the effectiveness of state health department chronic disease units.