A study recently published in Neurology suggests that hormone replacement therapy (HRT) might delay cognitive decline in women. More than 2000 women aged 65 and over were examined for their cognitive skills and symptoms of depression over a period of three years. The results now published indicate that HRT maintains cognitive function in older women (particularly in those over age 85) who are free of dementia, a group that is especially prone to cognitive loss. In spite of the positive effects of HRT in this study, the overall benefit of a lifetime of HRT is still an elusive possibility, and more detailed clinical and biochemical studies are required to determine the effects of HRT in preventing Alzheimer's disease and ameliorating age-related cognitive decline. At present, two clinical trials are underway in a collaborative effort between Johns Hopkins University (MD, USA), Utah State University, Duke University Medical Center (NC, USA), and the University of California, San Francisco. (Neurology 57, 2210–2216). SS