Lamotrigine (Lamictal, GlaxoSmithKline) is a recently developed anticonvulsant which has been investigated for efficacy in bipolar disorder. Increasing evidence indicates that it may have a different therapeutic profile than more established first-line mood stabilizers such as lithium and valproate. In particular, evidence from well-designed trials suggests efficacy for acute management and prophylaxis of bipolar depression but not mania. However, clinically relevant drug interactions and side effects can occur with lamotrigine, including benign to serious rash. The objectives of this drug profile are to review the basic chemical and pharmacological characteristics of lamotrigine, critically examine the growing body of research literature on its clinical use in the treatment of bipolar disorder, and review the safety and tolerability of lamotrigine as well as drug interactions relevant to clinical practice. Practical recommendations regarding titration and the management of rash are offered.