Objective: To develop and test the validity of the Behavior, Environment, and Changeability Survey (BECS) for identifying the importance and changeability of nutrition, exercise, and stress management behavior and related aspects of the environment. Design: A cross-sectional, online survey of the BECS and selected validated instruments. Setting: Ten state universities. Participants: A convenience sample of college students (n = 1,283), ages 18-24 years. Analysis: Principal component analysis was used to confirm a 6-component structure of the BECS in 2 independent samples for the purpose of cross-validation. Internal consistency was measured and construct and criterion-related analyses were conducted to test the reliability and validity of the BECS subscales. Results: Six components representing 34 BECS items were revealed from the original 69 items and explained 64% of the total variance. Six scales were retained, and internal consistency of each ranged from alpha = 0.82 to 0.93. BECS Nutrition Behavior and Nutrition Changeability scale scores were highest for participants in action/maintenance Stages of Change for fruit and vegetable intake. Conclusions and Implications: There is strong support for the use of the BECS when planning health programs to gain insight into behavior that young adults are willing to improve, specifically related to nutrition, exercise, and sleep. (Contains 4 tables.)