Medullary sponge kidney (MSK) is known as a congenital disesase with dilatation of collecting tubules. MSK is usually asymptomatic but various clinical manifestations may occur including nephrocalcinosis, renal tubular acidosis, impaired urine concentrating ability, urinary tract stones and infections. Although MSK is a congenital disorder, it is usually diagnosed in second or third decade. A 53-year-old woman presented with recurrent dysuria and bilateral costovertebral pain radiating to the groin region. Pyuria and hematuria were found. On ultrasonography, hyperechogenic densities of multiple calculi in the calyces of both kidneys, and minimal pelvicaliectasis were detected. Computed tomography revealed multiple punctate calcifications aligned concentrically in the medulla of both kidneys. On clinical and radiological grounds, the diagnosis of MSK was established. The patient's complaints were resolved with antibiotherapy for urinary tract infection. Thiazide or potassium citrate was not prescribed since hypercalciuria or hypocitraturia was not present. In conclusion, MSK should be considered in the differential diagnosis of nephrocalcinosis, nephrolithiasis and recurrent urinary tract infections in older patients, even in the fifth decade.