This chapter focuses on recent developments in the construction of optical sensors based on intelligent molecularly imprinted nanomaterials. The first two parts review the general principles in the development of molecularly imprinted polymer (MIP)-based optical sensors. Four different ways to transform the binding events into measurable optical signals are discussed. In the third part, nanosized MIP materials are classified as nanoparticles (including core-shell nanoparticles), nanofibres/nanowires/ nanotubes and nanofilms. The principle, analytical properties and applications of recently reported optical sensors based on above three different nano-MIP formats are all reviewed in detail. Finally, some of the remaining unsolved issues to the nano-MIP-based optical sensors are briefly discussed for further development of the field.