The effect of pressure on the resistivity of Agl -cAuc solid solutions has been measured up to 4 kbar in the temperature range 4 to 273 OK. Solid and fluid helium were used as the pressure transmitting media. The pressure derivatives of the total resistivity, e-l de/dP, for the alloys in th3 concent,ration range c = 0.1 to 0.9 were observed to be negative and to increase in magnitude wii h increasing temperature. It is shown that the magnitude and sign of @-l de/dP is primarily determined by the pressure derivative of the residual resistivity.