Background: There is currently no general self-report measure for assessing hygiene behavior. This article details the development and testing of such a measure. Methods: In studies 1 to 4, a total of 855 participants were used for scale and subscale development and for reliability and validity testing. The latter involved establishing the relationships between self-reported hygiene behavior and existing measures, hand hygiene behavior, illness rates, and a physiological marker of immune function. In study 5, a total of 507 participants were used to assess the psychometric properties of the final revised version of the scale. Results: The final 23-item scale comprised 5 subscales: general, household, food-related, handwashing technique, and personal hygiene. Studies 1 to 4 confirmed the scale's reliability and validity, and study 5 confirmed the scale's 5-factor structure. Conclusions: The scale is potentially suitable for multiple uses, in various settings, and for experimental and correlational approaches. © 2009 Association for Professionals in Infection Control and Epidemiology, Inc.