In the early 70's, improvements in methodical procedures of extraction and standardization of ginkgo preparation allowed the production of a highly concentrated and stable extract (EGb 761) (definition see editorial) by the company Dr. Willmar Schwabe, which could be systematically tested in scientific programs. Consequently, numerous studies have been undertaken and provided replicable outcomes to demonstrate its efficacy in human population. EGb 761 is currently registered as an ethical drug in more than 50 countries around the world, and is prescribed for a range of neurological and vascular disorders including dementia, arterial occlusive disease, retinal deficit, and tinnitus. The following chapter will focus on the relevant data that support EGb 761 efficacy in the treatment of cognitive disorders in general, and dementia in particular. Besides the published data, the author will provide original results unveiling different factors that could interfere with EGb 761 efficacy and may be the source of the variations observed among studies in the EGb 761 literature. In the author's opinion, such factors should be taken into consideration when implementing the design of future research and optimizing individual EGb 761 response in the clinical practice. Within the framework of this new approach, the author will not only answer the question as to whether EGb 761 works over placebo in cognitive disorders, but also attempt to estimate how well it works in particular conditions.