Objective: The objective of this study was to review the available literature for dexmedetomidine sublingual film use in the treatment of acute agitation associated with schizophrenia and bipolar disorders. Data Sources: A literature search of PubMed (January 2017-March 2023) and EMBASE (January 2017-March 2023) was performed using the terms: Igalmi, dexmedetomidine, schizophrenia, bipolar disorder, and agitation. Additional information sources include ClinicalTrials.gov, scientific posters, and articles identified through review of references from clinical trials publications. Study Selection and Data Extraction: Relevant English-language articles conducted in humans were considered, with a preference for phase 3 clinical trials. Trial analyses and articles discussing pharmacology, pharmacokinetics, efficacy, and safety were also evaluated. Data Synthesis: Dexmedetomidine sublingual film was evaluated for use in schizophrenia in the SERENITY 1 pivotal trial and for bipolar disorders in the SERENITY 2 pivotal trial. Both studies found treatment of mild to moderate agitation with dexmedetomidine sublingual film 180 and 120 μg to be superior to placebo in reducing the severity of agitation. Treatment effect was seen as early as 20 minutes. Somnolence was the most common adverse effect in both studies. Cardiovascular adverse effects were mild and transient in most cases. Relevance to Patient Care and Clinical Practice: Dexmedetomidine sublingual film is a new and novel treatment for agitation and gives clinicians an alternative to antipsychotic and benzodiazepine use. It has advantageous properties including its noninvasive route of administration, fast absorption, and rapid onset of effect. Cost may limit its use. Conclusion: Dexmedetomidine sublingual film provides an alternative approach to treatment of acute agitation in adults with schizophrenia and bipolar disorders based on both mechanism of action and route of administration.