The polymerization of acrylamide in an inverse microemulsion has been studied by time resolved fluorescence measurements. The reaction was initiated by thermal and by photochemical decomposition of the initiator AIBN. A decrease of the fluorescence lifetime of the probe molecule pyrenetetrasulfonic acid sodium salt was observed. In case of the photochemically initiated reaction two distinct lifetimes could be separated. The corresponding pre-exponential factors showed a good correlation with the gravimetrically obtained conversion. During the thermally initiated polymerization the fluorescence decays as well as the intensity of the scattered light were measured on-line and analyzed by a mono-exponential decay law.