Anaphylaxis is a rapidly fatal complication of anesthesia, and it needs to be appropriately diagnosed and treated by anesthesiologists. A 37-year-old man underwent surgery for pneumothorax under general anesthesia. Postoperatively, the train-of four count was four, and sugammadex was administered. Soon after, the patient's oxygen saturation and blood pressure decreased, and skin flushing was noted. We suspected anaphylaxis and administered adrenaline. Once the blood pressure normalized, we administered hydrocortisone, famotidine, and d-chlorpheniramine maleate. Thereafter, his condition stabilized, he recovered well, and he was discharged. Blood samples obtained after the onset of the episode indicated anaphylaxis, and a prick test performed 10 weeks postoperatively confirmed sugammadex as the causative agent. We report a case of sugammadex-induced anaphylaxis, which we could properly diagnose and treat because an anaphylaxis kit was available in our department.