This paper develops a model-reference adaptive controller (MRC) design framework for magnetically suspended vehicles (maglev) using the criterion of stable maximum descent. The adaptation algorithm is constrained to reduce the airgap error between the reference model and the actual system. The explicit relationship between the parameters of the performance criterion (function of the airgap error and its derivative) and the state feedback adaptation rule is derived for a single degree-of-freedom suspension system. Experimental results from a small representative test-rig are presented to illustrate the effectiveness of the proposed non-linear controller in the presence of variations in pay-load (suspended mass), disturbance force and airgap set-point. Hardware aspects of the transputer and DSP-based real-time controller are briefly discussed to highlight some of the practical issues related to digital implementation of the airgap adaptive control law.