We describe a rare case of Lyme disease complicated by unilateral neuroretinitis in the right eye. We report a case of a 27-year-old woman with blurred vision on her right eye. Because of the suspicion of optic neuritis (multiplex sclerosis) neurological examination was ordered. Surprisingly, computer tomography of the brain revealed incomplete empty sella, which generally results not monocular, but bilateral optic nerve swelling. Opthalmological examination (ophthalmoscopy and optical coherence tomography) indicated not only monocular optic nerve, but retinal oedema next to the temporal part of the right optic disk. Visual evoked potentials (VEP) demonstrated no P100 latency delay and mild differences between the amplitudes of the responses of the left and right eye. Optical coherence tomography (OCT) demonstrated the swelling of the optic nerve head and oedematous retina at the temporal part of the disk. Suspicion of an inflammatory cause of visual disturbance blood tests was ordered. Doxycycline treatment was ordered till the result of the blood test arrived. The Western blot and ELISA test were positive for Borrelia burgdorferi sensu lato. Following one week corticosteroide and ceftriaxone treatments, the patient displayed a clinical improvement. Unilateral neuroretinitis with optic disk swelling due to neuroborreliosis is a rare complication and in many cases it is difficult to distinguish between inflammatory and ischemic lesions. Further difficulty in the diagnosis can occur when intracranial alterations such as empty sella is demonstrated by CT examination