This article reports that the kinetics of surface-initiated atom transfer radical polymerization can be quantified by the quartz crystal microbalance with dissipation (QCM-D) technique. The kinetics of in situ growth of poly(oligoethylene glycol methylmethacrylate) monitored on a gold-coated QCM-D sensor chip revealed that changes in the experimentally observed frequency (DeltaF) and dissipation (DeltaD) as a function of polymerization time were a function of the initiator density, and that the experimental response could be predicted from a continuum model.