Bipolar disorder is a severe and chronic illness affecting approximately 1.5 valproate, carbamazepine and lamotrigine, bipolar disorder is characterized by high rates of recurrence, as treatment with these and other drugs is ineffective for and not tolerated by a significant percentage of patients. Several hypotheses have been postulated to explain the mechanism(s) of action of mood stabilizers. However, the biological and molecular bases of the disease are not fully understood, hampering the development of more effective and safer drugs. A large body of evidence associates lipids (cholesterol, phospholipids and fatty acids) with the mechanism and pathology of bipolar disorder. The purpose of this paper is to review the lipid connection to bipolar disorder.