Background: Highly potent dopamine D(2) receptor antagonistic antipsychotics may induce hyperprolactinemia. Conversely, drugs for the treatment of prolactinoma may activate dopamine D2 receptors, which can induce or aggravate psychosis. Aripiprazole, as a partial D(2) receptor agonist, may be the drug of choice in patients suffering from both psychosis and prolactinoma., Objective: We evaluated the effects of aripiprazole on the size of a cystic macroadenoma by magnetic resonance imaging and on prolactin levels in a patient suffering from psychosis and prolactinoma., Method: This is a case report of a 53-year-old female patient with a chronic psychotic disorder and moderate mental retardation who had developed a prolactinoma that was resected but still had residual adenoma and hyperprolactinemia. Antipsychotic medication was switched from risperidone to aripiprazole before a dopamine agonist was initiated., Results: After change in treatment, there were reductions in serum prolactin levels, tumor size and visual field defects. We observed no psychotic decompensation., Conclusion: The combination of aripiprazole and quinagolide could be considered as an effective treatment in patients suffering from both psychosis and a prolactinoma., (Copyright © 2012 Elsevier Inc. All rights reserved.)