Authors reviewed the theoretical history of the "motivation" construct, and its utilization within past/current health behavior research. Textbooks and review articles functioned as sources for the theoretical history review. Research published within a 10-year period (1993-2002) in four health promotion journals (all with impact factors greater than or equal to 1.0) comprised the systematically reviewed data. Only empirical studies containing the term "motivation" in the title/abstract were included. Studies were excluded if they did not examine motivation as a focal variable and/or assessed non-health behaviors. Data abstracted included the definition of motivation; theoretical framework; measurement tool(s) used; type of behavior being studied; and indicators measured. Abstracted data were coded and organized into a matrix. Data matrixes were qualitatively assessed. Among reviewed studies, only four (9%) provided a definition of motivation. Only eleven studies specifically measured motivation despite all included studies having "motivation" in the title/abstract (25%). The most common indicator used to measure motivation was intention. While seventy-three percent of the studies (n = 32) were theory-based, 21 different theories were used. Eleven of the studies (25%) focused on preventive behaviors (n = 11). The studies reviewed varied in the conceptualization and measurement of motivation. Such variability may significantly affect the development and evaluation of motivation-focused interventions. (Contains 1 table and 2 figures.)