AbstractAn alternate development of the quasilinearization method for parameter estimation is presented to enable a more efficient implementation of the algorithm. Similarity of this algorithm to Gauss‐Newton method is shown and attention is given to systems having a nonlinear relationship between the observed and state variables. To overcome the problem of a small region of convergence, the use of direct search optimization is proposed for the first few iterations, followed by the simplified quasilinearization algorithm.