BackgroundFreeman-Sheldon syndrome (FSS) is a rare disorder characterized by specific deformities of the extremities and face. There have been no reports of open-heart surgery in pediatric patients with FSS.Case presentationWe present the case of an 8-year-old girl with FSS who underwent atrial septal defect closure. Tracheal intubation was uncomplicated, although the patient had microstomia. Inhalational anesthetics and dopamine antagonists were avoided intraoperatively and perioperatively. We chose dexmedetomidine as an adjuvant for postoperative pain management contributing to adequate analgesia and early extubation without causing respiratory depression.ConclusionsAnesthetic management of FSS requires consideration for airway management and prevention of malignant hyperthermia and respiratory complications. We successfully managed the case avoiding the use of malignant hyperthermia-triggering drugs.