Vancomycin is a safe, effective antibiotic for a variety of serious gram-positive infections. Because of emerging vancomycin-resistant enterococci and the threat of spread of vancomycin-resistant genes to other gram-positive organisms, judicious use of vancomycin should be promoted. Trimethoprim-sulfamethoxazole, a broad-spectrum synergistic combination, continues to find widespread use in gram-negative bacterial infections, especially involving the urinary tract. It has enjoyed enormous success in prophylaxis and therapy of Pneumocystis carinii pneumonia. Rifampin remains of paramount significance as a cidal agent against Mycobacterium tuberculosis; however, increasing reports of strains of MDR-tuberculosis are of great concern.