Bipolar disorder is a devastating illness that affects the quality of life for millions of Americans. The current diagnostic system depends on an extremely subjective interview and can frequently result in an incorrect diagnosis and ineffective treatment. An improved, biologically based, classification system requires a thorough understanding of the genetic basis of bipolar disorder. This understanding has been hampered by the difficulty in diagnosing patients and by the heterogeneity of the illness. The number of linkage analysis studies and lack of organization have also added to the challenges involved in understanding the biological basis of the disorder. The Bipolar Disorder Genetics Database web application, located at http://www.bipolardisordergenetics.com, resolves the issue of organization, allowing researchers to quickly identify promising chromosomal regions that merit further investigation which will lead to understanding the functions of the affected genes and the impact of the various mutations. Understanding these functions will lead to significant advances in the areas of diagnosis and treatment. The intuitive web-based interface is a novel approach to creating a big picture view of our existing knowledge. The application will become the premiere resource for researchers and will assist them as they make significant advances in treating this illness