In this paper, a complete electro-thermal analysis is presented for the metal-oxide-metal antifuses. The application of the Wiedemann-Franz Law and the thin film effect on thermal and electrical conductivities of metal films were also discussed. Several key parameters for tungsten-oxide-tungsten antifuse were extracted. The reaction temperature between tungsten and oxide was estimated to be around 1300°C. The core resistivity was found to be around 250 μω -cm. This model can be readily extended to the other metal-dielectric-metal systems.