Introduction: Cabergoline is a highly effective dopamine agonist agent to reduce prolactin levels. It has adverse side effects such as cardiovascular, gastrointestinal, and neuropsychiatric common to other drugs of the same category. However, in international literature, there are few reports of patients that develop a mania episode. This case is possibly the first of mania induced by cabergoline reported in Brazilian medical literature. Case Report: Patient, N.M.G.F., was identified with high prolactin levels and, after an investigation, a pituitary microadenoma was diagnosed. The medical conduct prescribed was Cabergoline 0.25 mg twice a week (as reported in the medical record). After 24 days of treatment, the patient's wife reported a relevant behavioral change, consistent with a manic episode. Due to that, Cabergoline was suspended and Lithium Carbonate was administered. The clinical condition evolved with symptom improvement. Discussion: There are few facts that support the association of Cabergoline administration with developing symptoms of mania. The correlating of mania and brain dopaminergic pathways are recognized and Cabergoline, which is a dopaminergic agonist can stimulate these pathways. Besides that, the patient did not have a familiar or personal record of mania and did not use any other medication that could cause these conditions. Lastly, as the patient showed this symptom 3 weeks after the first administration of the medication and got better rapidly as well after he stopped taking the pills and started using Lithium Carbonate. For this reason, we can ratify the diagnostic hypotheses. To summarize, the behavioral change must be observed and questioned by Cabergoline users. Even though it is a very safe and effective medication to reduce prolactin levels, it could induce psychiatric side effects associated with it.