The purpose of this article is to provide an overview of the current state of research in the area of treatment integrity as it relates to behavioral consultation. To this end, four primary topics are discussed. First, a rationale for why treatment integrity is an important professional and methodological concern is presented. Second, conceptualizations of treatment integrity as a dimensional construct and methods for assessing treatment integrity are reviewed. Third, variables hypothesized to moderate treatment integrity and the empirical basis for several strategies to promote treatment integrity are summarized. Finally, the relationship between treatment integrity and outcomes is discussed. Research from related fields that may influence thinking and practice related to treatment integrity within behavioral consultation are discussed throughout. (Contains 1 figure.)