Forests of the W-UI exist in a people-dominated landscape. As such, their existence and character are highly sculpted by the values, perceptions, and motivations of people. They exist in spatial and temporal dimensions similar in part but often dissimilar from those experienced in more rural forestscapes. Each forest reflects differing values and requires/affords different levels of human involvement through management for forest health. Forests of the W-UI are often highly fragmented and altered, both physically and socially. They often exist in an environment of constrained options (reflecting an increasing disconnect from forestry infrastructure), social disincentives to management, and heightened concerns for safety and liability.: - Forest Health is defined in part by science and in part by social perspective. - Forest Health can be considered according to varying spatial, temporal, and value dimensions. - Most definitions of Forest Health would include considerations of sustain ability and satisfaction of objectives. - Forest Health can be impaired by environmental factors, cultural practices, and pathogens and insects. - Environmental factors include inadequacy of edaphic and biotic resources, altered disturbance regimes, modified species composition, and changes in abiotic environmental elements. - Cultural factors include the use or the failure to use available silvicultural practices. Indigenous and introduced pathogens and insects act as primary agents as well as stress-response agents. - Guidelines for maintaining enhancing Forest Health are founded in clearly defined objectives, are mindful of environmental and cultural factors, are designed to minimize ‘stress*, and are based on understanding the biology and ecology of pathogen and insect 'adversaries' -- and their response to environmental and cultural factors. These elements comprise the basis of a prevention approach to managing Forest Health in the W-UI.