The austenite formation kinetics in unalloyed cast ductile iron was studied on the basis of dilatometry measurements, and Avrami’s equation was used to estimate the material’s kinetic parameters. A continuous heating transformation diagram was constructed us-ing heating rates in the range of 0.06 to 0.83°C?s?1. As the heating rate was augmented, the critical temperatures, c1A and Aα, as well as the intercritical range, which was evaluated as the difference between the critical temperatures, α c1Δ T =A ?A , increased. At a low heating rate, the kinetics of austenite formation was slow as a consequence of the iron’s silicon content. The effect of heating rate on k and n, the kinetic parameters of Avrami’s equation, was also determined. Parameter n, which is associated with nucleation sites and growth geometry, de-creased with an increase in heating rate. In addition, parameter k increased with the increase of heating rate, suggesting that the nucleation and growth rates are carbon-and silicon-diffusion controlled during austenite formation under continuous heating.