One-lung ventilation for thoracic procedures in patients with a "difficult airway" can pose special problems for an anaesthesiologist. Case report: 27 year 50 kg, known case of Myasthenia Gravis was scheduled for robotic thoracoscopic thymectomy. Airway examination revealed mouth opening of 4.5 cm, MMC II along with buck teeth. One lung ventilation was required because of left sided thoracic surgical approach. After induction of anaesthesia, laryngoscopy revealed a CL II glottic view.