Alkalinization and d penicillamine were administered to 24 patients with cystine lithiasis. The follow up period was 1-20 years. As gauged by the frequency of nephrectomy, urolithotomy, renal colics, stone expulsion, X ray findings, kidney function and urinary tract infection, the overall results appeared satisfactory. D penicillamine in combination with alkalinization was more effective than the latter alone, but side effects of d penicillamine were common. A policy of treatment is given: alkalinization and, when ineffective, addition of d penicillamine.