This article presents a summary of available data on the use of quetiapine extended release (QUE-XR). QUE-XR is an example of an atypical antipsychotic drug that can be used in a single dose, thereby simplifying the treatment regimen. From the therapeutic standpoint, this issue is of paramount importance, since approximately 50% of patients have adherence issues. Therefore, availability of the drug which is comfortable in administration can significantly improve treatment outcomes. Due to its antipsychotic, antidepressive, mood stabilizing and anxiolytic efficacy, QUE-XR seems to be a promising drug with potentially broad spectrum of indications (in patients with schizophrenia, bipolar disorder, major depression and some anxiety disorders – both in the acute phase of treatment, and the maintenance treatment). Notably, QUE-XR seems to ameliorate sleep disturbances, and it may also improve patients’ quality of life (as suggested by some studies). Due to the simple dosing regimen of QUE-XR, conducting therapy with this drug may contribute to the improvement of compliance. Yet, the primary clinical criterion for selection of the type of formulation of quetiapine should be the individual preferences of the patient, and the knowledge and experience of the treating physician.