Forest managers faced with incorporating the maintenance of biodiversity into their analyses, plans, and decisions need reliable, quantitative measures of biodiversity. This paper reviews and critiques quantitative approaches that have been developed to measure the three basic attributes of diversity: species richness, heterogeneity, and evenness. These approaches are discussed in terms of application to fine- and large-scale land areas. The advantages and disadvantages of each measure are described relative to forest management. Habitat modeling, which combines aspects of both fine- and landscape-scale analysis, may hold the greatest potential for monitoring forest-level diversity in ways that are meaningful, measurable, and manageable.Key words: biodiversity, quantitative indices, forest management.