Two brothers are described with renal tubular acidosis and nerve deafness: the elder also had rickets and hypokalaemia. The parents were unaffected. Studies of urinary acidification and bicarbonate excretion were consistent with a distal tubular abnormality. This report strengthens the view previously proposed in similar cases that nerve deafness and renal tubular acidosis constitute a genetic entity. Examination for nerve deafness is indicated in any child with renal tubular acidosis.