The new anticonvulsant, lamotrigine, is becoming an important tool in the treatment of bipolar disorder, including bipolar depression. Its efficacy in bipolar depression might be linked to its inhibition of serotonin uptake. We present the case of a female schizoaffective patient successfully treated with 400 mg of lamotrigine developing considerable genital disorder, a side effect well known from the treatment with selective serotonin reuptake inhibitors (SSRIs). We suggest that female genital disorder induced by high doses of lamotrigine is a serotoninergic side effect.