In this paper the problem of sensorless control for permanent magnet synchronous motors (PMSMs) with uncertain parameters is considered. The designed approach is based on adaptive flux and position observer with fixed-time convergence and uses classical field-oriented controller. It is assumed, that stator currents and control voltages are measurable signals and the only known motor parameter is the stator inductance. Presented estimation algorithm is based on Kreisselmeier’s dynamic extension of the regressor with suitable mixing and ensures fixed-time estimation of the motor fluxes, position and stator resistance. The efficiency of the proposed solution is compared with state observer that uses dynamic regressor extension and mixing algorithm. The improvement of transient behavior is demonstrated via simulation results.