We report on findings from a 2-year follow-up study of immigrants originating from exposed areas around the site of the 1986 Chernobyl accident matched with comparison subjects emigrating from other republics in the Confederation of Independent States. In the initial study of 708 immigrants, the samples were matched by age, gender, and year of immigration. We assessed two exposure groups--high and low--by estimating levels of ground cesium contamination from the International Atomic Energy Agency maps. We reinterviewed 520 immigrants from the first wave of data collection (a reinterview rate of 73%), 87 from high-exposure areas, 217 from low-exposure areas, and 216 comparison subjects. This study examined the prevalence of symptoms of posttraumatic stress disorders (PTSD), depression, somatization, anxiety, and physical effects (high blood pressure, acute symptoms, and chronic illness). The results obtained in the first wave conducted 8 years after the accident showed that psychological symptoms were significantly higher in exposed respondents than in the comparison group. During the second wave (10 years after the accident) we observed a decline in the prevalence of PTSD and related distress except for somatization, which remained at the same level. An association between exposure and high blood pressure was observed in the first wave of data, but was not still significant in the second wave of data collection. The proportion of those who reported three or more chronic health problems was 48.3% among the high-exposure group, 49.3% in the low-exposure group, and 30.6% in the comparison group (p = 0.0003). The most commonly reported problems were heart disease. problems with vision or hearing, migraine headaches, problems with the lymphatic system, and arthritis. Based on the results, it was concluded that the Chernobyl accident was a powerful stressor, having a strong impact on both mental and physical health. Since all respondents were engaged in the process of acculturation and accommodation to a new country after emigration, it is encouraging that this study shows that levels of psychological distress are waning as the new immigrants are absorbed into Israeli society. However, there still remains some independent effect on health associated with the experience of the Chernobyl accident.