Molecularly imprinted polymers (MIPs) are materials mimicking biological receptors in their specific recognition of analytes. Although molecular imprinting has been around for over 30 years, recently this technology has made rapid developments. However, recent investigations have led mainly to the synthesis of new polymers imprinted for a wider range of compounds without real and better understanding of the mechanisms occurring during the polymerisation and the recognition process. This review covers work developed in understanding these mechanisms and presents different strategies utilised in optimising MIP design.