This paper discusses the need for screening programs to identify seriously emotionally disturbed students and describes the development and trial of a screening instrument for identifying probable cases from among possible cases. The Quick Screening Inventory (QSI) is a brief, easy-to-use instrument that is directly related to the definition of serious emotional disturbance in Public Law 94-142. The Law requires that the public schools identify all handicapped students, including those determined to be seriously emotionally disturbed. The development and initial reliability testing of the QSI, which contains 45 paired "yes/no" items, involved its administration to graduate students and included the administration of a test evaluation instrument to teachers. The QSI was demonstrated to have adequate reliability for a screening instrument. A screening trial was conducted in a small school system of 107 teachers and 1,746 students that was without serious emotional disturbance services. The school population was 35% black and 65% white. The trial was initiated in the spring after teachers had taught students for a long enough period to apply the duration criterion used by the instrument. The QSI identified 1.6% (n=28) of the system's student population as being probable cases of serious emotional disturbance. Students identified with the QSI were reassessed with the Behavior Problem Checklist (Revised); 96% (n=27) of the identified cases were confirmed as probable cases of severe emotional disturbance. The QSI is provided. (TJH)