Substituting or adding fluoroquinolones to established first-line antituberculous drug regimens gives no additional benefit or risks. Fluoroquinolones have antituberculous activity, but are not one of the standard antituberculous medicines. Ciprofloxacin, ofloxacin, levofloxacin, and sparfloxacin have been tested in randomized controlled trials. Ciprofloxacin should not be used as a substitute drug in the standard antituberculous regimen, as more people with drug-sensitive tuberculosis had relapses and it took longer for them to be cured, although it was no different in terms of cure or number of adverse events. Sparfloxacin was no better than ofloxacin when added to antituberculous regimens in drug-resistant tuberculosis. Further trials are warranted.