Corticosteroids are widely prescribed for a variety of medical conditions. Accumulating evidence suggests that their use may be associated with adverse psychiatric effects, including mania. In this systematic review, we aim to critically evaluate the existing literature on the association between corticosteroid use and the emergence of mania. We conducted a comprehensive search of major electronic databases (PubMed, Embase, Cochrane Library) for relevant studies published up to the date of the search (January 12, 2023). Inclusion criteria involve studies that investigate the association between corticosteroid use and the emergence of mania in adult patients. The primary outcome is the prevalence of (hypo)mania following corticosteroid administration. Secondary outcomes include potential risk factors, dose-response relationships, and differences among various corticosteroid formulations. The identified studies were subjected to a systematic selection process and data extraction by an independent reviewer. A total of 47 articles met the inclusion criteria for our systematic review. Our findings suggest that mania is a common side-effect of corticosteroid use, particularly in prednisone equivalent doses above 40 mg. These findings hold practical significance for clinicians and provide insights into potential interventions, including careful monitoring, dose adjustments, and consideration of psychotropic medications when managing corticosteroid-induced mania.