Bactrim, which is a combination of trimethoprim and sulfamethoxazole, is a widely prescribed antibiotic and is used for treating a wide range of infections caused both by gram negative and gram-positive bacteria. Despite its effectiveness, Bactrim is associated with several adverse effects, one of which includes hyponatremia. Hyponatremia is an uncommon complication of treatment with trimethoprim-sulfamethoxazole (Bactrim).[1] Hyponatremia is less common with low-dose Bactrim and can occur in about 17.5% of patients. Bactrim induced hyponatremia is especially prominent in elderly patient’s with other comorbidities like hypothyroidism, chronic kidney disease, history of being on thiazide diuretics. We report a case of a 75-year-old female who presented with confusion and ataxic gait secondary to hyponatremia after she was treated with Bactrim for cellulitis.