Gentamicin is an aminoglycoside with a wide spectrum of antibacterial activity. However, as a highly water-soluble drug, it penetrates cells poorly. This constitutes a particularly important drawback for treating intracellular bacterial infections. This major hurdle may be solved by the use of vectors to deliver and target bioactive agents to the intracellular sites of infection. Thus, in the case of antimicrobials, drug delivery systems may help to increase their therapeutic index in intracellular locations. The development and evolution of pharmaceutical forms of gentamicin for the parenteral treatment of intracellular pathogens is reviewed in this paper.