A new state reconstructor for deterministic digital control systems is presented which is ideal in the following sense: if the plant parameters are known exactly, the output of the new state reconstructor will exactly equal the true state of the plant, not just approximate it. Furthermore, this ideal state reconstructor adds no additional states or eigenvalues to the system, nor does it affect the plant equation for the system in any way; it affects only the measurement equation. While there are countless ways of choosing the ideal state reconstructor parameters, two distinct methods are described here. An example is presented which illustrates the procedures for completely designing the ideal state reconstructor using both methods.