Objective: The mental health effects of major terrorist attacks on diplomatic government personnel have not been well studied. This study examined the psychiatric and psychosocial effects of the 1998 terrorist bombing of the US Embassy in Nairobi, Kenya, on US government personnel exposed to the bombing. Method: At 8-10 months after the bombing, 179 US government employees (53 Americans, 126 Kenyans, 53% male, age mean = 40.6 and SD = 8.4 years ranging 21-65) were assessed with the Diagnostic Interview Schedule for DSM-IV for disaster-related psychiatric diagnoses and the Disaster Supplement Interview and Questionnaire about their immediate disaster experiences, subjective responses, mental health interventions/treatment, safety perceptions, and coping. Results: About one-third (32%) of these US government personnel developed postdisaster psychiatric disorders, mostly bombing-related PTSD (20%), but few received psychiatric treatment. Prevalence rates of all postdisaster psychiatric disorders, including bombing-related PTSD, were similar between subgroups of Americans and Kenyans, despite the Kenyans reporting more direct disaster trauma exposures, subjective postdisaster distress, and posttraumatic stress symptoms. These US government personnel had fewer psychiatric consequences of the Nairobi bombing than their previously studied civilian counterparts. Conclusions: Possible explanatory factors in the lower prevalence of postdisaster psychopathology in these government personnel compared to the civilians are selection for greater personal resilience for government employment and stigma-based underreporting of mental health needs in governmental workplaces. Stigma is a potential barrier to psychiatric treatment that needs to be addressed in government workplaces.