Pulmonary drug delivery is the preferred route of administration in the treatment of respiratory diseases and some nonrespiratory diseases. Recent research has focused on developing structurally stable high-dosage drug delivery systems without premature release. To maximize the deposition in the desired lung regions, several factors must be considered in the formulation. The special issue includes seven papers deal with aerosol-assisted fabrication of nanostructured particles, aerosol deposition, nanoparticles pulmonary exposure, and controlled release.