Inhalation of aerosols represents the most frequently used drug delivery method for the treatment of lung diseases. To further improve drug efficacy in the lungs, it may be advantageous to control aerosol deposition and target aerosols to diseased or disease-causing lung tissue and cellular structures in order to maximize drug potency and minimize side effects in unaffected tissue. We have recently investigated a novel method which brings aerosol delivery to an advanced level of specificity by making use of magnetic gradient fields to direct magnetizable aerosol droplets containing superparamagnetic iron oxide nanoparticles (SPION) specifically to desired regions of the lungs in mice. In this chapter, we will present a detailed description of this procedure for application in mice.