In this paper, the asymptotic properties of tracking systems incorporating linear multivariable plants which are amenable to high-gain error-actuated control (Porter and Bradshaw 1979) are characterized in terms of the eigenstructure of the closed-loop plant matrices. It is shown that the closed-loop eigenstructure is such that the tracking behaviour of systems incorporating high-gain error-actuated controllers designed in accordance with the synthesis technique of Porter and Bradshaw (1979) is increasingly dominated by the modes associated with the first-order infinito characteristic roots as the gain is increased and that increasingly ‘ tight ’ control is therefore achieved. These theoretical results are illustrated in the case of a closed-loop system incorporating a third-order plant and a high-gain error-actuated controller by the presentation of the computed closed-loop eigenstructure and of the results of computer simulation studies.