Mucoadhesion, the state in which two materials, amongst which one is biological in nature, adhere to each other for extended periods of time with the help of interfacial forces, provides an attractive strategy to overcome the hurdles of conventional drug delivery systems including first pass metabolism, and localized delivery of biomolecules including proteins, peptides and oligonucleotides. Mucoadhesion provides great opportunities for the delivery of a variety of compounds via different routes of administration viz. ocular, nasal, vaginal and buccal. In addition mucoadhesion also makes it possible to obtain prolonged, local or systemic drug action. In this review we discussed about potential applications of mucoadhesion and mucoadhesive polymers in drug delivery along with the mechanism of mucoadhesion and the methods for evaluation of mucoadhesive drug delivery systems. (C) 2016 Elsevier B.V. All rights reserved.