OBJECTIVES: To estimate the economic consequences of replacing Seroquel (the normal tablets of quetiapine) with Seroquel XR® in the treatment of bipolar disorder in Poland. METHODS: Based on the established model of the economic consequences of bipolar disorder treatment, we calculated the cost of treating bipolar disorder with quetiapine in Poland. Expenditures for the purchase of medicines, hospital costs and the costs of lost productivity were highlighted. The analysis was performed from a societal perspective, taking into account the Payer’s perspective, in three–year time horizon. RESULTS: The use of Seroquel XR® will decrease hospitalisation rate and length of hospitalisation, what will reduce direct costs of bipolar disorder treatment by PLN 645 thousands (161 thousands Εuro). The use of Seroquel XR® will increase the population of patients who comply with the recommended treatment, which will reduce the likelihood of suicide, absenteeism, and the disability pension. The budget savings related to indirect costs reduction are estimated at PLN 15,3 million (3825 thousands Euro). Moreover, the reimursement of Seroquel XR® would decrease the social transfers by  PLN 157,6 thousands (39,4 thousands Euro) in comparison to current scenario. CONCLUSIONS: The reimbursement of Seroquel XR® with the reimbursement limit at the level of the reimbursement limit for normal tablets of quetiapine is profitable for the state budget – it will not only bring budgetary savings, but also allow patients to return to active life, which is crucial in the case of bipolar disorder.