The growth kinetics of the isothermal omega phase in Ti–6.8Mo–4.5Fe–1.5Al can be monitored by the continuous measurement of the electrical resistivity as shown in our previous publication in this Journal. The rate law for the growth of these isothermal omega particles radius r_iso is obtained assuming the resistivity to be proportional to the surface of the interface between the beta matrix and the quasi spherical isothermal omega particles. The rate law r³_iso∝t is observed at the beginning of the growth process, that is before the interaction of the outward diffusion fields from the particles. A mathematical model based on a diffusional transfer of the beta stabilizers from the ω_iso particles through the interface between the ω_iso particles into the beta matrix is developed. The growth rate slows down when the outward diffusional fields from the particles interact. Ostwald ripening is not observed.