A method determining a rate of recirculated exhaust gas (EGR rate) at an inlet of a cylinder of an internal combustion engine at a moment t, the exhaust gas being conveyed in a recirculation duct connecting an exhaust line of the engine to an intake line, and the EGR rate being equal to the ratio between flow rate of the recirculated gas and total gas flow rate in the intake line at a location of the intake line in question and at the moment in question. The method: a) determines at which moment t_intro preceding the moment t the gas, having arrived at the inlet of the cylinder at moment t, was fed into the intake line; b) determines the EGR rate at an outlet of the recirculation line to the intake line at the moment t_intro; and c) determines the EGR rate at the inlet to the cylinder at moment t based on the EGR rate at the outlet of the recirculation line to the intake line at moment t_intro, as determined in b).