The need exists for a psychometrically sound measure of individuals' evaluative/affective body image states. In the present investigation with 174 college students, the six-item Body Image States Scale (BISS) was developed and found to be acceptably internally consistent and moderately stable. Evincing its convergent validity, the BISS was appropriately correlated with various trait measures of body image. It was sensitive to reactions in positive versus negative situational contexts. Sex differences reflected those expected from the literature. Construct validity was confirmed by an experiment on persons' differential reactivity to appearance-related information as a function of level of dysfunctional body-image investment. The BISS is a unique and much-needed measure with potential utility in both research and clinical work.