The frontal dynamics of the sorption and desorption of the antibacterial antibiotic erythromycin on molecularly imprinted monoliths on the base of 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate and on non-imprinted analog was investigated. In contrast to large molecules, the sorption of the antibiotic was determined not only by convective mass transfer, but also by gel diffusion into weakly cross-linked regions of the polymer sorbents and molecular imprinting of monoliths polymer matrix resulted in an increase in gel diffusion. At desorption from molecularly imprinted polymeric monoliths, an individual front of erythromycin desorption from specific imprint sites was observed.