Background: Congenital insensitivity to pain with anhidrosis is a rare autosomal recessive disorder characterized by hyperpyrexia, anhidrosis, pain insensitivity, self-inflicted injuries, and intellectual disability. The anesthetic management of these patients is challenging owing to the high risk of perioperative complications resulting from their autonomic dysfunction, such as hyperthermia, hypotension, and bradycardia, which result from autonomic nervous system dysfunction. Case presentation: Two 3-year-old Han Chinese identical male twins (weighing 13.5 kg and measuring 93 cm tall) were previously diagnosed as having congenital insensitivity to pain with anhidrosis based on clinical features and genetic screening. According to the presence of loud snoring and heavy breathing during sleep and neck radiograph findings, they were diagnosed as having tonsil and adenoid hypertrophy and needed adenotonsillectomy. Because of innate analgesia, some reports suggested that patients with congenital insensitivity to pain with anhidrosis do not require perioperative pain control. Accordingly, our patients did not receive opiates. We describe the general anesthetic management of these patients using sevoflurane and propofol, but without opiates, for adenotonsillectomy. Remarkable tachycardia and hypertension occurred during airway manipulation and when the surgical stimuli increased, and their temperatures increased from 36 °C and 36.8 °C to 37.8 °C and 38.5 °C, respectively. Patients with congenital insensitivity to pain with anhidrosis lack pain sensation, but they may have tactile hyperesthesia. Surgical noxious stimuli may therefore produce a stress response and unpleasant sensations, leading to hemodynamic fluctuation and temperature increase. Conclusions: On the basis of these findings, we suggest that careful intraoperative opiate titration may be justified to blunt the surgical stress response and promote hemodynamic and temperature stability in similar patients; we also recommend the preparation of warming and cooling devices and continuous temperature monitoring in these patients. Since anesthetic management of these patients is not simple, careful attention is required. © 2017 The Author(s).