This study examines the effect of a major event (terrorist attacks) on the stereotypic perceptions, attitudes and affects of 119 Israeli adolescents (56 males and 63 females of 5th and 8th grades) toward three target groups: (a) Palestinians, who still have conflictive relations with the Israelis (Palestinian extremists carried out the attacks), (b) Jordanians, who have peaceful relations with the Israelis and (c) Arabs, in general, who are considered a subcategory including Arabs of all nations. The questionnaires were administered to the same adolescents three times: during a relatively peaceful spell in Israeli–Palestinian relations; one day following two terrorist attacks, and three months thereafter. In the last administration adolescents' need for closure was also measured. Adolescents' perceptions, attitudes and affect toward the three target group were differentiated—relating to Palestinians most negatively and to Jordanians most positively. Also, following the terrorist attacks, stereotypic perceptions and attitudes changed in a negative direction, in relation to all the three groups; again with expressed differentiation among the three groups. In the third measurement, some measures remained negative, but some changed to be more positive. Only few effects of age were detected and several significant correlation with need for closure were found. These results indicate that stereotypes and attitudes toward outgroups are context-dependent, influenced by events; thus they serve as ‘a seismograph’ to the quality of intergroup relations at any given time. Copyright © 2001 John Wiley & Sons, Ltd.