This paper describes a method of identifying the parameters of a continuous-time system, which is described by a first-order differential equation with dead time. The continuous-time process is approximated by a discrete-time difference equation, using interpolation polynomials to approximate the continuous-time input signals of the process to be identified. The convolution theorem is used to determine a difference equation. The number of parameters remains the same; the original parameter of the continuous-time system can be computed uniquely from the estimated parameters of the equivalent discrete-time system. The method is applied to the determination of the moving mass and the friction forces of a hydraulic drive.