Introduction: Guillain-Barré Syndrome (GBS) is a neurological disorder associated with ascending paralysis due to damage to the peripheral nerves by the immune system. Hyponatremia is the most common electrolyte disorder encountered in patients with GBS admitted to the Neurointensive Care Unit (NICU). Hyponatremia is associated with a poor outcome, prolonged hospital stay, and increased hospital cost. Linezolid is an oxazolidinone antibiotic used against gram-positive bacteria. The main adverse effect limiting its use is the development of myelo suppression; however, it can also cause hyponatremia. Aim: To investigate the incidence of hyponatremia in GBS patients treated with linezolid. Materials and Methods: This was a retrospective study conducted in a 14-bedded NICU at the National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India, over a period from January 2017 to January 2018. All patients with GBS who received linezolid therapy were included in the study. Out of 46 admitted patients, 16 received linezolid therapy. Final data were available for 12 patients. Hyponatremia was defined as sodium