Parasomnias are a group of disorders characterized by abnormal behaviors, physical activities, and autonomic arousal symptoms while transition to sleep or continuation of sleep. Sleep terror (ST) is classified under parasomnias characterized by sudden fear attacks beginning with crying attacks or high-frequency screams and continuing with increased autonomic symptoms. ST occurs in the first few hours of sleep during the delta phase. Further, the lifetime prevalence of ST in adults is less than 1%. It is important to obtain; anamnesis from patients' bed partner for a clinical evaluation of ST. Methods, such as evaluating sleep diaries and video recordings, can help ST diagnosis. It is also important to evaluate patients' medical history, history of substance or alcohol abuse, psychological traumatic experiences, primary or secondary incomes, and detailed neurological aspects. Physician can select some serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants (TCADs) as medical treatment if patients have a high frequency of attacks. Because of addiction and relapse of ST episodes, benzodiazepines are not preferred as the first-line treatment. In this study, we will discuss ST, which is rare in adulthood, and use of long-acting benzodiazepine based on two cases.