College student-athletes have unique life stress that warrants close attention. The purpose of this study was to develop a reliable and valid measurement assessing college student-athletes' life stress. In Study 1, a focus group discussion and Delphi method produced a questionnaire draft, termed the College Student-Athletes' Life Stress Scale. In Study 2 and Study 3, the properties of the items and the underlying structure of the College Student-Athletes' Life Stress Scale were confirmed through item analysis, factor analysis, and reliability examination. A 24-item College Student-Athletes' Life Stress Scale with eight factors was established. In addition, examining concurrent and discriminant validity via correlations among College Student-Athletes' Life Stress Scale, positive state of mind, and burnout experiences provided further evidences of criterion validity. Across these phases, results showed adequate factorial structure, criterion validity, and reliability of the College Student-Athletes' Life Stress Scale. The investigators suggest that College Student-Athletes' Life Stress Scale could be used as a tool for researchers and practitioners to assess college student-athletes' life stress. (Contains 2 tables and 1 figure.)