In response to concerns about occupational and environmental exposures, and a perceived cluster of amyotrophic lateral sclerosis (ALS) in the community, the mortality experience among 31,811 civilian employees who worked for at least 1 year between 1981 and 2000 at Kelly Air Force Base, Texas was ascertained. A total of 3264 deaths occurred through October 31, 2001. Overall, significant deficits in mortality were observed for all causes of death and all cancers combined. An excess of breast cancer [standardized mortality ratio (SMR) = 216; 95% confidence interval (CI) = 128–341] among blue-collar women was identified, and remained elevated after adjusting for race and ethnicity [rate ratio (RR) = 2.83; 95% CI = 1.50–5.34]. Mortality from motor neuron disease, which includes ALS deaths, was not increased overall (SMR = 0.98; 95% CI = 0.52–1.68), and was lower among blue-collar employees and higher among white-collar employees than expected, based on small numbers. Overall, mortality patterns indicated a healthy worker population and no large increased mortality associated with employment at Kelly Air Force Base.