SUMMARY
Nalidixic acid was given by intravenous infusion to 50 patients with infected urine; 1 g. of the sodium salt was diluted with at least 500 ml. saline and given 3 times a day for 1–4 days. There were no side effects. The full 14‐day course was then completed by mouth. Results were excellent in half the patients, with sterile urine 14 days after completion of the course.