In this paper we address the problem of state observation for sensorless control of magnetic levitation systems, that is, the regulation of the position of a levitated object measuring only the voltage and current of the electrical supply. Instrumental for the development of the theory is the use of parameter estimation based observers, which combined with the dynamic regressor extension and mixing parameter estimation technique, allow the reconstruction of the magnetic flux. With the knowledge of the latter it is shown that the mechanical coordinates can be estimated with suitably tailored nonlinear observers. Replacing the observed states, in a certainty equivalent manner, with a full-state feedback stabilising law completes the sensorless controller design. In the interest of brevity the result is presented only for a two-degree-of freedom system but the approach is applicable also for the more familiar case of one-degree-of-freedom. Simulation results are used to illustrate the transient performance and robustness of the proposed scheme. (C) 2018 Elsevier Ltd. All rights reserved.