A method for controlling a rotatable-drum laundry drier to dry laundry in a drum is provided. The control method includes the steps of memorizing, in a memory device of the laundry drier, a comparison threshold variable in time according to a predetermined profile, and, at predetermined drying times in the laundry drying cycle, measuring an electric quantity indicating the moisture in the laundry at the drying time; comparing, at each drying time, the measured electric quantity with the memorized comparison threshold corresponding to the drying time; and determining the end of drying cycle time on the basis of this comparison.