INTRODUCTION AND DEVELOPMENT. Alzheimer's disease (AD), the leading cause of dementia, is a complex disorder in which genetic and environmental factors interact. Three genes -the amyloid precursor protein (APP) and the presenilin 1 and 2 (PSEN1 and PSEN2)- have been linked to autosomal dominant forms of AD. Besides, a fourth gene -the apolipoprotein E gene (APOE)- seems to be the only major genetic factor related to late-onset sporadic and familial AD cases. Although more than a thousand studies have been performed to date, little is known about other genetic factors leading to this devastating dementia. Nevertheless, the last three years have witnessed a surge in genetic research of AD due to the implementation of novel technologies enabling large-scale genetic analyses. CONCLUSION. This review provides a summary of current knowledge about AD in the genetic field.