Alzheimer's disease (AD) is the most common cause of dementia and accounts for one-half to three-fourths of all cases of dementia. In the United States, AD is the leading cause of a loss of independent living and subsequent institutionalization. Approximately 4 million Americans are currently diagnosed with Alzheimer's disease—which results in greater than $100 billion dollars in health care costs. This review provides a description of the cognitive and neuropathological features of AD and the challenge that aging populations around the globe pose to health care systems and to societies. A review of new and promising therapeutic strategies for the prevention of AD is discussed which includes estrogen replacement therapy and anti-inflammatory therapeutics. Pharmaceutical approaches that delay the progression of the disease, such as antioxidants, are discussed as well as therapeutic strategies for improvement of cognitive function in AD patients, including the new generation of compounds aimed at enhancing cholinergic function. This section is followed by a review of the current status on nerve growth factor trials. The final section addresses the issue of the genetic linkages of AD, the impact of transgenic and gene knockout mouse models of AD on research in the field and the potential use of gene therapy to treat AD.