A kinetic model based on a detailed reaction mechanism for the nitroxide-mediated radical polymerization (NMRP) of styrene is presented. The reaction mechanism includes the following reactions: chemical initiation, reversible nitroxyl ether decomposition, monomer dimerization, thermal initiation, propagation, reversible monomeric and polymeric alkoxyamine formation (production of dormant species), alkoxyamine decomposition, rate enhancement, transfer to monomer and dimer, as well as conventional termination. By simple manipulation of the ODEs initial conditions and tuning of the model by turning on/off the appropriate kinetic steps via their corresponding kinetic rate constants, the model presented here is capable of representing two technologically important variations of nitroxyl mediated polymerization techniques: 1) use of traditional radical initiator together with a nitroxide-type stable radical; and 2) use of a nitroxyl ether or alkoxyamine compound as controller. Model predictions are validated against experimental data provided by Ciba Specialty Chemicals, Inc. Parametric sensitivity analyses and non-linear estimation procedures are used to estimate the unknown kinetic rate constants. The overall agreement between model predictions and experimental data is generally good. The qualitative simulations and the detailed mechanistic discusssions presented here provide deeper insight into some of the aspects of NMRP processes not well understood to date.