The Magnetoresistive properties of sputtered Ni8.1Fe1.9/Ag Multilayers have been investigated as a function of both Ag and NiFe layer thicknesses and thermal treatments. For the virgin sample, the Magnetoresistance (MR) ratio at room temperature goes through a maximum of 17% for a Ag thickness of about 11 A. In addition, the R (H) curve is found to be perfectly linear and reversible. Contrary to the MR ratio, the saturation field is observed to decrease continuously as the Ag thickness increases, leading to an increasing slope of the R (H) curves. Upon annealing, we observe both an increase of the MR ratio and a decrease of the saturation field, leading to a three fold increase of the MR slope for annealing temperatures of 280°C. Such a behavior appears to be highly dependent on the layer thicknesses.