Objectives: Episodes of psychotic agitation are frequent in patients with dual diagnosis, that is, in patients with concomitant psychiatric and substance use disorders. Rapid intervention is needed to treat the agitation at a mild stage to prevent the escalation to aggressive behavior. Inhaled loxapine has been demonstrated to rapidly improve symptoms of mild-to-moderate agitation in adults with psychiatric disorders (schizophrenia and bipolar disorder), but data on patients with dual diagnosis are scarce. Methods: This study is a retrospective review of data from a case series of patients with dual diagnosis, which were attended for symptoms of agitation while at the emergency room (n = 9), in the outpatient clinic (n = 4), or during hospitalization (n = 1) at 1 center in Spain. All patients received inhaled loxapine for treating the agitation episodes. Results: Data from 14 patients with dual diagnosis were reviewed. All patients had 1 or more psychiatric disorders (schizophrenia, bipolar I disorder, drug-induced psychotic disorder, posttraumatic stress, borderline or antisocial personality disorder, depression, or anxiety) along with a variety of substance use disorders (alcohol, cocaine, cannabis, amphetamines, hypnotics and antianxiety drugs, caffeine, or street drugs). Overall, only 1 dose of inhaled loxapine (9.1 mg) was needed to calm each patient during an acute episode of agitation. Conclusions: Inhaled loxapine was rapid, effective, and well accepted in all dual-pathology patients presenting with acute agitation in the emergency setting. Inhaled loxapine facilitated both patient cooperation and an adequate management of his or her disease.