A method for treatment of bacterial infections with rifalazil administered once-weekly or twice-weekly. A method for treatment of tuberculosis caused by Mycobacterium tuberculosis, infections caused by Mycobacterium avium complex, infections caused by Chlamydia pneumoniae and infections caused by Helicobacter pylori by administering to a patient suffering from the bacterial infection 1-100 mg of rifalazil once or twice a week. In this dose regimen, the treatment is fast, efficacious and eliminates undesirable secondary symptoms observed with daily doses of 1-50 mg of rifalazil.