In this chapter, the published articles pertinent to therapeutic applications of inhalable proliposome drug delivery systems, or liposomes generated from proliposomes were reviewed and summarized. It was found that these applications focused highly on pulmonary infectious diseases such as tuberculosis, pseudomonas infections and fungal infections. Incorporation of a wide range of hydrophilic (e.g. aminoglycosides) and hydrophobic (Amphotericin B) antibiotic drugs into proliposome formulations was discussed, and the role of formulation including carrier type, lipid composition and inclusion of bioadhesives was evaluated. The potential of proliposomes in the treatment of pulmonary infections is derived from the established success and FDA approval of the non-proliposomal liposome formulation of amikacin (Arikayce®) designed for the treatment of Mycobacterium avium complex (MAC) pulmonary infection. Importantly, the application of proliposome drug delivery systems for the treatment of other diseases was also highlighted, such as asthma, cancer, and in gene therapy. The promising findings achieved with proliposomes including in vitro investigations and in vivo studies using experimental animals, suggest possible clinical investigations to take place in the future.