Fourteen 3-arylimidazo[1,2-a]pyridines were used as fluorescent molecular sensors for monitoring free radical and cationic photo-polymerization by fluorescence probe technique. The p-substituted 3-phenylimidazo[1,2-a]pyridines (R = NH2, OMe, Me, SMe, H, OCF3, CF3, COMe, CN and NO2) as well as 3-arylimidazo[1,2-a]pyridines (aryl = 1-naphthyl-, 9-anthracenyl-, 9-phenathrenyl- and 1-pyrenyl) were used in the study. All of the derivatives studied (except for 3-(4-nitrophenyl)imidazo[1,2-a]pyridine and 3-(4-acetylphenypimidazo[1,2-a]pyridine) were good enough as fluorescent probes for monitoring free radical photopoly-merization. The OMe, H, Me, SMe and COMe-substituted 3-phenylimidazo[1,2-a]pyridines as well as 3-(1-naphthyl) and 3-(9-anthtacenyl)imidazo[1,2-a]pyridines were suitable for monitoring the cationic photopolymerization.