Aminoglycosides remain the cornerstone of prophylaxis and therapy against the majority of aerobic gram-negative organisms responsible for serious sepsis in the hospital. Gentamicin, tobramycin, amikacin are all equally efficacious against susceptible organisms and differ only in their patterns of resistance and pharmacokinetic profiles. The ototoxic and nephrotoxic potential of gentamicin, tobramycin, and amikacin is comparable. Amikacin appears to be preferred for general use at present because of its low resistance potential and superior pharmacokinetic profile (high and predictable serum peaks, wide toxic-therapeutic ratio, high "kill ratio," and q 12 h dosing). In spite of the introduction of the third generation cephalosporins, which are highly active against a variety of aerobic gram-negative organisms, the aminoglycosides will continue to play an important role in the treatment of gram-negative infections. Indeed, the expected usefulness of aminoglycosides may be prolonged by the introduction of the third generation cephalosporins since these drugs will probably be used in combination with aminoglycosides to extend spectrum and to take advantage of possible synergy.