Over the past 50 years, molecularly imprinted polymer nanoparticles (MIP NPs or nanoMIPs) have undergone remarkable advancements in both synthesis approaches and applications. Renowned for their binding properties, which rival those of antibodies, they have earned the monikers of “antibody-mimics” or “synthetic antibodies”. Thanks to innovative synthesis strategies, MIP NPs have emerged as powerful tools for in vitro and in vivo applications, particularly in the realms of imaging and therapy. This chapter comprehensively summarizes the major concepts pertaining to the utilization of nanoMIPs in imaging and therapy. It encompasses a wide range of imaging applications, including single-photon, multi-photon, multiplexed, and multimodal imaging, where MIPs demonstrate their efficacy. Also, this chapter presents diverse therapeutic concepts, such as drug reservoirs and targeted drug delivery systems for cancer therapy, encompassing chemo- and radiotherapy, chemo-/photodynamic, thermal therapy, and antimetabolic therapy. Moreover, it delves into the novel concept of drug-free polymer therapeutics utilizing MIP NPs. The current challenges and valuable insights into future perspectives are also be discussed.