A 13-item Dissociation scale is introduced, and preliminary data regarding its reliability are presented. Designed to complement the Symptom Checklist (SCL-90; Derogatis, Lipman, & Covi, 1973) and the Hopkins Symptom Checklist (HSCL; Derogatis, Lipman, Rickels, Ulenhuth, & Covi, 1974), this scale may be especially useful in research on the effects of psychological trauma.