This paper describes a self-report measure, the Child Abuse and Trauma Scale, which yields a quantitative index of the frequency and extent of various types of negative experiences in childhood and adolescence. Data on this measure are presented for two large samples of college students and for a small clinical sample of subjects with a diagnosis of Multiple Personality Disorder. The strong internal consistency and test-retest reliability of the scale in the college population is documented, and its validity is attested to by demonstrating that it correlates significantly with outcomes such as dissociation, depression, difficulties in interpersonal relationships, and victimization, all of which have previously been associated with childhood trauma or abuse. The extremely high scores of the Multiple Personality subjects confer additional validity to the measure. The authors suggest that the construct of psychological maltreatment underlies the destructive elements of numerous forms of abuse and neglect, and that the scale they have developed may provide a useful index of this construct.