Abstract: Background: Sulfonamides are a commonly prescribed class of antibiotics for the treatment of urinary tract infections (UTIs). Sulfadiazine, in particular, has been associated with the formation of crystals in urine, which can lead to kidney stones and urinary tract obstruction. Objective: To report a case of sulfadiazine urine sediment in a patient with a history of recurrent UTIs. Method: We present a case report of a 45-year-old female with a history of recurrent UTIs who presented with the presence of sulfadiazine crystals in her urine sediment. The patient had been prescribed sulfadiazine for a recent UTI and had discontinued the medication as directed by her physician. Urine analysis revealed the presence of numerous sulfadiazine crystals, as well as leukocytes and bacteria. The patient was treated with antibiotics and instructed to drink plenty of fluids. Follow-up urine tests showed the disappearance of the sulfadiazine crystals. Results: The presence of sulfadiazine crystals in urine sediment was detected on routine urine analysis in a patient with a history of recurrent UTIs who had been prescribed sulfadiazine for a recent UTI. The crystals disappeared on follow-up urine tests after treatment with antibiotics and increased fluid intake. Conclusion: Sulfadiazine urine sediment is a rare complication associated with the use of sulfonamides for the treatment of UTIs. Clinicians should be aware of this potential complication and monitor for the presence of sulfadiazine crystals on urine analysis in patients who have been prescribed sulfonamide antibiotics. Appropriate management, including discontinuation of the medication and increased fluid intake, can prevent the development of kidney stones and urinary tract obstruction.Abstract: Background: Sulfonamides are a commonly prescribed class of antibiotics for the treatment of urinary tract infections (UTIs). Sulfadiazine, in particular, has been associated with the formation of crystals in urine, which can lead to kidney stones and urinary tract obstruction. Objective: To report a case of sulfadiazine urine sediment in a patient...Show More