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It is well known that antipsychotic drugs could lower the seizure threshold. It has been shown that quetiapine causes significantly less EEG abnormalities compared to other antipsychotics. Lithium is a proconvulsant agent but apparently used safely in epileptics with bipolar disorder. Although lithium and quetiapine monotherapies seem to be safe in epileptic bipolar patients, the combination therapy of lithium with antipsychotics needs to be used cautiously because of induced seizure risk. In this article we presented a case of epileptic seizures induced by a combination therapy of quetiapine and lithium. The patient was 28 years old and had been admitted to our psychiatry clinic because of depressed mood, loss of energy, fatigue, irritability, loss of interest, insomnia and psychomotor retardation. He has had epilepsy for 16 years. He had used valproic acid for 5 years. He has got no seizure for 4 years. His depressive episode was exacerbated 6 months ago. At the time of admission, the patient was not under medical treatment. His first medical treatment was lithium. He has gone under lithium monotherapy for only 2 months. He had no seizure while he was using lithium monotherapy. In his recent history; he underwent seasonal mood şuctuations with the symptoms of insomnia, decreased need for sleep, elevated mood, increased energy, distractibility, irritability and impulsivity. He became extremely talkative, hyperactive and he began to squander money in spring and summer. Bipolar disorder I, depressive episode was diagnosed according to the (DSM)-IV-TR. Lithium and quetiapine treatment was started. After 2 weeks of treatment the patient had many seizures in a day. He had a humeral fracture due to an epileptic seizure and his EEG showed generalized epileptiform activity. Lithium and quetiapine were stopped and valproic acid was started. In a study that investigated the risk of EEG abnormalities associated with the use of various antipsychotic drugs; EEG abnormality risk was particularly high with clozapine and olanzapine, moderate with risperidone and typical neuroleptics, and low with quetiapine. In another study, the effects of the atypical antipsychotics quetiapine and olanzapine and the typical antipsychotic haloperidol on EEG patterns were retrospectively investigated in 81 patients. EEG abnormalities seemed to occur rarely in patients treated with quetiapine comparable to the control group. In a clinical trial with 3700 patients, the occurrence of seizures in patients treated with quetiapine was no greater than that observed in patients receiving placebo. Although lithium–neuroleptic combination treatment is largely safe, there is growing evidence that some patients were sensitive to such combination and at increased risk of significant and disturbing side-effects. The most important hypotheses are that lithium- antipsychotic treatment might cause neurotoxicity by increasing dopamine receptor blockade. Our patient was using lithium and quetiapine concurrently. He has not had any epileptic seizures for the last four years until the seizures were induced with the use of quetiapine and lithium. We suggest that Lithium- antipsychotic treatment should be used with caution, as this combination treatment might be associated with a relatively greater risk of seizures. The probability of induction of seizures with Lithium- antipsychotic treatment should always be kept in mind.