Molecular imprinting of polymers, a cross-linking polymerization of functional monomers in presence of a template, yields synthetic materials mimicking the function of biological receptors [1]. The controlled photoinitiated synthesis of thin layers of molecularly imprinted polymers (MIPs) [2] offers many possibilities for development of novel composite materials for affinity technologies (Fig. 1). Molecularly imprinted membranes have a very large, but almost unexplored potential for substance-specific separation, analytics or catalysis [3]. Our aim is the rational design of structure and function of MIP affinity membranes. Our main approach is the controlled functionalization of porous polymeric, especially microfiltration and track-etched membranes to synthesize novel MIP composite membranes (Fig 2).