Drawing upon research which conceptualizes anger as a multidimensional construct including three associated components-anger experience (affective anger), hostility (anger cognitions), and anger expression (aggression, assertion, and withdrawal)-the preliminary development of a Multidimensional School Anger Inventory (MSAI) for adolescents is described. This scale is a modification and extension of the School Anger Inventory and was developed to assess the affective, cognitive, and expressive aspects of anger using items having school-relevant content. Data were collected through personal interviews of 202 males from three different schools: School 1 included general education students in a parochial school in grades 6 through 12; School 2 included students attending general education or mainstreamed special education classes at a public intermediate school; and School 3 included students participating in a public day treatment program for youths with serious emotional disturbance. Scale development is discussed focusing on item development and scale refinement through item and factor analyses. Four factors were identified that accounted for 43.3% of the common variance. Anger Experience, Cynical Attitudes, and Anger Expression were identified as major clusters with the anger expression items bifurcating into Destructive Expression and Positive Coping components. The resulting 31-item scale has strong psychometric qualities and appears to have promise for use in research, treatment planning, and outcome evaluations.