This paper presents a model describing the hysteresis in ferroelectric materials at moderate to high driving levels. Hysteresis and nonlinearities are attributed to the irreversible displacement of domain walls. The model, based on a simple mechanism related to the dry-friction concept, is developed to describe the hysteresis of polarization and strain under electric field and stress. Besides coefficients such as epsilon(33) and d(33) also exhibit large hysteresis loops under high electric and/or mechanic level. In this paper it is shown that modeling macroscopic quantities such as P or S hysteresis lead to a reasonable estimate of the coefficients since their behavior depends mainly on polarization. The proposed approach is developed, discussed, and compared with experimental results from Navy II piezoelectric transducer ceramic. Comparisons on hysteresis loops are given and are in good agreement for the polarization and strain versus electric field and, to a less extent, for the coefficients epsilon(33) and d(33). The linear and Rayleigh regime are deduced from the proposed approach. (C) 2004 American Institute of Physics.