Transnasal endoscopic orbital decompression is emerging as a new minimally invasive technique that avoids the need for cutaneous or gingival incision. This surgical approach appears to be a safe and effective procedure, even for the treatment of ocular disease, and it can be performed under general or local anaesthesia. The authors present a case of severe monolateral non-Graves' axial exophthalmos, accompanied by severe anisometropic myopia, which was treated successfully with functional endoscopic sinus surgery. The minimally invasive surgical procedure resulted in a marked reduction of exophthalmos without any severe complications and with minimal discomfort for the patient, who was discharged from hospital on the fourth postoperative day.