In a long-term hospital 50 patients were treated with Tibirox, a bactericidal drug consisting of 100 mg tetroxoprime and 250 mg sulfadiazine. 39 of the patients were given Tibirox for urinary tract infections and 11 for respiratory diseases. The treatment lasted for 14 days but was extended up to 42 days in cases involving a risk of reinfection (indwelling catheter) or obvious chronicity of the complaint; and in some cases the therapy was continued at a reduced dosage of one half tablet once daily. 72 percent of the patients with urinary tract infections responded well or satisfactorily to the treatment. It is pointed out that most patients with indwelling urethral catheters are transferred to us from acute hospitals. Due to this unsatisfactory situation there is inevitably a large risk of infection. As a hospital in charge of the further treatment of such patients, often over a long period, we seek to remove the catheters if possible and to cure the infections. We have used Tibirox in numerous cases as a drug of first choice because it offers the following advantages: it has a bactericidal effect, a broad spectrum of activity, is well tolerated, easy to dosage, and conveniently to take. Since our patients have in most cases undergone previous therapy, it is considered to take an antibiogramme. In urgent cases treatment with Tibirox is started before the results have been received and then continued in accordance with the sensibility test results or the clinical response to the therapy. All patients suffering from sub-acute to chronic bronchitis showed an improvement after treatment with Tibirox and relief of symptoms over longer periods.