Renal tubular acidosis resulting in metabolic acidosis is rarely reported in India. We present 13 cases related to urinary stone disease. This study is based on analysis of the data of 138 patients with hypercalciuria out of 2005 stone patients who attended the stone clinic at the Medical College Hospital, Trivandrum over a period of 12 years (1980–1991). Of these patients, 69 with bilateral renal stones or recurrent stone disease with more than three incidents or hypercalciuria without evidence of hyperparathyroidism were submitted to an acid load test. All patients had sterile urine and a complete stone metabolic work up for stone disease.