Introduction: Unipolar mania (UM) is a disorder that behaves differently from bipolar-I disorder (BP-I), however, it is not considered an independent entity by current diagnostic manuals, but rather included within the diagnosis of BP-I. Case report: A 21-year-old man presented a 3-month-long episode characterized by exalted mood and mood-congruent psychotic symptoms. The patient denies previous depressive episodes. Treatment with lithium and aripiprazole was established, which was satisfactory, not showing recurrence after 5 years of follow-up. Literature review and discussion: Diagnostic manuals describe that to diagnose BP-I the presence of a major depressive episode is not required, which implies that patients with UM fall into the same diagnostic category as patients with BP-I. Differences between UM and BP-I have been demonstrated in epidemiological, clinical, and genetic studies, therefore, including heterogeneous patients within the same category could hinder the interpretation of studies and limit advances in the knowledge of both disorders. Conclusion: Based on the literature review, it is suggested that UM should be recognized as an independent diagnosis. Despite its low prevalence, by validating it as such, in the future we could have more and better-quality data about this diagnosis. In this way, its distinctive characteristics can be defined more concretely, and therefore improve the clinical approach of these patients.