This paper introduces the fluorogenic molecule N-(2-anthracene)methacrylamide, AnMA, employed as a probe for monitoring radiation-induced polymerization in situ. The relative reactivity of AnMA during free radical polymerization of methyl methacrylate (MMA) has been determined via fluorescence techniques. The ratio between propagation rate constants for the reaction of an MMA free radical chain-end with AnMA relative to the reaction with MMA is found to be 0.96. It is demonstrated that AnMA can be used for monitoring MMA polymerization quantitatively throughout the entire course of the reaction including the gel effect region. Results are also provided which demonstrate that AnMA can be used for sensitive monitoring of MMA polymerization both in bulk and in solution. (C) 2003 Elsevier Ltd. All rights reserved.