22 male volunteers (aged 22-49 yrs) in Jerusalem were given a psychological test battery at the height of the Iraqi Scud missile attacks on Israeli cities during the 1991 Persian Gulf War and again after hostilities ceased. Venous blood samples were taken at each time point. Psychological testing indicated levels of anxiety were higher during the war than they were after the war ended, and both anxiety and anger during the hostilities were significantly elevated compared with prewar datDuring the war, specific war-related pressures were greater than everyday pressures, and problem-focused coping was more evident than emotion-focused coping. Natural-killer cell activity and cell-mediated Iympholysis were significantly elevated during the war, as were plasma levels of adrenocorticotrophic hormone, neurotensin, and substance P. The only biological test parameter found to be reduced during the war was mononuclear cell thymidine incorporated in nonstimulated cultures.