OBJECTIVE: The authors investigated the impact of continuous and repeated stress on Israeli civilians exposed to missile attacks during the Gulf War. METHOD: Study 1 included 26 healthy volunteers aged 28-59 years. Their scores on the Hamilton Anxiety Rating Scale and levels of plasma cortisol and growth hormone (GH) were evaluated before, during, and after the war. Study 2 included 13 healthy volunteers aged 25-59 years. Their scores on the state portion of the State-Trait Anxiety Inventory and levels of cortisol and GH were measured three times daily (8:00 a.m., noon, and 6:00 p.m.) at two time points (during and after the war). RESULTS: Anxiety levels of civilians exposed to the threat of war and later to actual missile attacks were significantly higher before and during the war than afterward. Anxiety during the war reached a peak in the evening. The increase in anxiety was not accompanied by any change from basal morning cortisol and GH levels or by diurnal variations in these hormones. CONCLUSIONS: Anxiety levels during the war were similar to those 1 day before its onset, which can be explained by the nature of coping processes. During the war, anxiety levels were highest in the evening, reflecting the war routine (missile attacks occurred mostly at night). The unaltered hormone levels and their normal diurnal variations despite the subjects' persistent anxiety were probably due to adaptation of the hypothalamic-pituitary- adrenal and hypothalamic-somatotropin axes to continuous stress.