The basis for therapeutic strategies targeting the amyloid-β protein (Aβ) has come from studies showing that accumulation and aggregation of the Aβ within the brain is likely to cause Alzheimer's disease (AD). Along with an ever-increasing understanding of Aβ metabolism, many potential therapeutic strategies aimed at altering Aβ metabolism have emerged. Among the more intriguing targets for therapy are enzymes involved in cholesterol homeostasis, because it has been found that altering cholesterol can influence Aβ metabolism in experimental model systems, and that cholesterol-lowering agents, specifically HMG-CoA reductase inhibitors, could reduce the incidence of AD. It is likely that cholesterol influences Aβ metabolism in several ways, including altering Aβ production and perhaps altering Aβ deposition and clearance. Thus, pharmacological modulation of cholesterol levels could provide a relatively safe means to reduce Aβ accumulation in the brain, and thereby prevent or slow the development of AD.