In modeling semiconductor junctions the extraction of the model's parameters is often hindered by the presence of parasitic series resistance and shunt conductance. We propose a method to extract the intrinsic and extrinsic model parameters using the exact explicit analytic solutions for current and voltage of the junction's I-V characteristics, which are expressed in terms of Lambert W functions. However, direct numerical fitting of these solutions to extract the model's parameters would be an unwieldy and computationally inefficient task. To circumvent this difficulty, the proposed method is based on first calculating the Integral Difference Function, D, from the explicit analytic solutions for I and V. This produces a purely algebraic equation in I and V whose coefficients contain the model's parameters. The coefficients of this auxiliary equation can be quickly determined by direct numerical fitting. From them, all the intrinsic and extrinsic model parameters are then readily obtained at once. The method is tested on representative synthetic I-V characteristics to illustrate the computation process. (C) 2004 Elsevier Ltd. All rights reserved.