This has been an overview of the pharmacology of tobramycin, a new potent aminoglycoside, particularly active against Pseudomonas aeruginosa. Close attention must be given to the administration of this compound, and to the administration of all aminoglycosides, if one is to achieve adequate serum and tissue concentrations without provoking a toxic renal or otic reaction. Differences in methods and dosage of administration depending upon age, status of renal function, and route of administration are discussed. The basic principles reviewed can be applied to all the agents in this class.