To study the efficacy of the fluoroquinolone maxaquin (lomefloxacin), the latter was used in 27 patients with destructive bacillary pulmonary tuberculosis which progressed with routine drug regimens. After monthly therapy, positive clinical changes were achieved in 85.6% of patients, abacillation was obtained in 33.2%, a X-ray decrease in infiltrative and focal changes was recorded in 81.5% and decay cavitary closure occurred in 22.2% of patients at month 3 of maxaquin therapy. The positive clinical, laboratory, and X-ray changes occurring after the use of maxaquin necessitates the supplementation of this agent to the drug regimen for patients with progressive pulmonary tuberculosis. Mycobacterial resistance to the major drugs is an indication for the use of maxaquin.