The proper approach to diagnosis and management in patients with a first episode of a calcium-containing kidney stone is controversial, and we have reviewed the literature in a search for objective information. Six large retrospective studies show the "natural cumulative recurrence rate of renal stones" to be 14% at 1 year, 35% at 5 years, and 52% at 10 years. Randomized studies of the use of either thiazides or allopurinol suggest a modest beneficial effect of about 35% over placebo. Considering that the risk of this specific therapy is about 5%, the morbidity associated with renal stones is limited, and relatively less invasive procedures can often replace nephrolithotomy, we conclude that use of specific drug therapy, namely thiazides or allopurinol, is not warranted in patients with a first kidney stone and, therefore, that extensive metabolic evaluation is unnecessary.