To the Editor: The findings of Modlinger et al. (N Engl J Med 289:1022, 1973) on the use of propranolol in the management of a patient with Bartter's syndrome are somewhat different from our own. In our patient, an 8 1/2-year-old black boy weighing 17.5 kg, the diagnosis was made at one year of age on the basis of failure to thrive, metabolic alkalosis, hypokalemia with juxtoglomerular-cell hyperplasia on renal biopsy and hyper-reninemia. He had polydipsia and salt craving. On admission the serum sodium was 132, potassium 2.2, and carbon dioxide 34 mEq per liter, and the pH 7.58, with.