A five-item measure of value on health, a new variable in the Personality System of Problem-Behavior Theory (Jessor & Jessor, 1977), was construct-validated using cross-sectional data from 1588 male and female 7-12th grade students. Three aspects of construct validity were explored: first, the convergent and discriminant validity of the Value on Health Scale with other health-related psychosocial measures; second, the predictive validity of the Value on Health Scale in relation to health behaviors; and third, the theoretical validity of the Value on Health Scale in relation to other constructs reflecting conventionality-unconventionality in Problem-Behavior Theory. Value on Health related significantly to other health-related psychosocial measures such as self-description of health, and parental and peer models for health-enhancing behavior. Value on Health also related significantly to greater involvement in health-enhancing behaviors (e.g., regular physical exercise, seatbelt use, and attention to healthy diet). Finally, Value on Health was linked to a larger network of psychosocial and behavioral characteristics that reflect the underlying dimension of conventionality-unconventionality in the Problem-Behavior Theory framework. Value on health seems to be a useful addition to personality attributes that help explain variation in health behavior among adolescents. It would also seem to be an important target for prevention! intervention efforts with that age group.