In this paper, a methodology for simultaneous estimation of state variables and electrical parameters in induction motors is presented and illustrated by simulation and experimental results: the method consists in designing an observer for an extended system, obtained by transformation of a classical Park state-space representation of the motor. The transformation is computed so as to obtain a representation which is affine w.r.t. variables to be estimated. The method can be used to estimate the flux together with all the identifiable electrical parameters, with or without speed measurement. If the speed is not measured, it is estimated by the same approach. Simulation and experimental results illustrate the methodology performances for various estimation problems.