The synthesis of molecularly imprinted polymers (MIPs) presents a solution to the challenges faced in using biological receptors for chemical processes. This chapter delves into the foundational concept of molecular recognition and the critical need for synthetic receptors with enhanced stability and specificity. Molecular imprinting, a method for generating artificial macromolecular receptors, provides considerable potential in smart and efficient sensors able to identify and track specific molecular targets. MIPs display selective binding to templated molecules, similar to a “lock-and-key” mechanism, thereby emulating the recognition capabilities of biological receptors. The synthesis of MIPs entails a multi-stage process involving the interaction between template molecules and functional monomers, cross-linking, and the replication of the target molecule structures. This chapter highlights a comprehensive overview of synthesis techniques in molecular imprinting, ranging from bulk monoliths to nanoparticles, focusing on various methods such as polymerization in molds or layers, in situ electropolymerization and grafting approaches, as well as the production of patterned and pattern-supported macroporous MIP films. Additionally, it examines the synthesis of MIP nanoparticles (nanoMIPs) and nanogels, providing insights into their applications and future perspectives in the fields of chemical sensing and biomedicine.