The concept of mucoadhesion for the design of non-invasive drug delivery systems gained increasing attention in recent years. Within the current review, various mucoadhesive polymers, including poly(acrylates), chitosan, thiolated polymers and others, as well as their use in mucosal drug delivery are discussed. An emphasis has been put on the development of mucoadhesive formulations, and in particular on recently developed micro- and nanoparticulate systems. Moreover, the applications of the mucadhesive carrier systems for different administration routes such as the oral, nasal, pulmonary and ocular route are discussed.