Alzheimer's disease is the most common cause of dementia and is becoming a global health concern. Despite a well-established understanding of the molecular mechanism involved in its pathogenesis, and millions of dollars of investment in drug discovery and clinical trials, no single molecule has yet been approved for its treatment since the advent of cholinesterase inhibitors and memantine. This review examines first the optimal use of currently approved agents and then explores in detail the current Phase II and III clinical trial landscape, while spending some time on the mechanistic details. Driven by the increasing knowledge gleaned from numerous Phase III failures and improvements in early detection and biomarkers, there is renewed enthusiasm that a cure is taking shape along the visible horizon.