The effect of lateral asthenospheric viscosity variations on observable signatures related to postglacial rebound in the Barents Sea is studied. Using a finite-element approach to discretize the problem, a comparison between a laterally homogeneous reference earth model and a laterally heterogeneous earth model is performed. The results indicate that a change in asthenospheric viscosity of about three orders of magnitude influences predictions of land uplift up to 10--20 m, present-day velocities up to 0.5--1.5 mm/a, and present-day gravity anomalies up to 0.4--0.8 mGal in the northwestern part of the Barents Sea region. ¿ 1998 American Geophysical Union