Drug delivery systems (DDS) are based on the concept of providing the optimal amount of a drug to a specific area requiring treatment. Liposomes are lipid-based nanoparticles capable of encapsulating any drug into both their membrane and aqueous phases. They have the potential to be targeted when their surfaces are modified with functional molecules such as antibodies and peptides. Thus, liposomes have strong potential as drug carriers if designed for active targeting. Our research group has recently developed a new concept for liposome targeting called "reverse targeting DDS (RT-DDS)". RT-DDS differs from conventional active targeting in that the surface of the liposomes is modified with an antigenic molecule that is specifically recognized by antigen-specific immune cells. This review describes in detail the differences between these two DDS targeting concepts and proposes the application of RT-DDS to the treatment of allergies based on research using ovalbumin as a model allergy antigen.