In this work, the problem of understanding some underlying phenomena in microemulsion polymerization is addressed, with an integrodifferential (ID) approach combining notions and concepts from microemulsion kinetics and thermodynamics. The procedure is applied to previously reported experimental data on the polymerization of hexyl methacrylate (C(6)MA), n-butyl methacrylate (nC(4)MA), and styrene (STY), in microemulsions stabilized with dodecyltrimethylammonium bromide (DTAB), and a simple mechanistic three-parameter model is presented that is capable of describing all systems studied. It was found that (i) the nucleation rate does not follow a linear behavior with time as claimed previously, (ii) the propagation rate coefficient (k(p)) decreases at high conversions suggesting a pronounced vitreous effect, even in reactions where the glass transition temperature of the polymer is lower than the reaction temperature, (iii) radical entry to polymer particles is negligible, (iv) coagulation among particles can be disregarded, and (v) the interval corresponding to the rate decrease is also caused by a reduction of active sites.