Micro and nano hydrogels developed from natural and synthetic polymers have garnered great deal of attention in sci- entific and industrial realms due to their higher surface area, degree of swelling and active material loading capacity, softness and flexibility, as well as their similarity to natural tissues. Particularly, biocompatible, non-toxic, and biodegradable micro/nano vehicles with tailor made design and functionalization facilitates their use with excellent feasibility for a variety of biomedical applications such as tissue engineering, bioimaging and drug delivery. However, these platforms require rational design and functionalization strategies to cope with barriers of in vivo environment to pass into clinical use. Firstly, an ideal carrier should be biocompatible, and capable of evasion from immune elimination, specifically target at desired sites and sustainably release the therapeutic cargo in response to microenvironment conditions. Despite the few setbacks in micro/nano vehicle design and several successful formulations translated to clinical use and majority of the carries are yet to achieve complete success for all biological criteria. In this review, design and functionalization strategies of micro and nanogels have been summarized. Also, the recent progress in biomedical applications of microgels and nanogels have been outlined with a primary focus placed on drug and biomolecule delivery applications.