Abstract
The electrical resistivity of the intermetallic compounds LaAg, CeAg and YAg has been measured in the range 10-800 K. The data on YAg are described by the usual Block-Gruneisen formula, but both CeAg and LaAg show higher resistivity values and a different thermal dependence. These anomalies can be ascribed to valence instabilities of the two rare earths, but, unlike most phases with unstable cerium and ytterbium atoms, the corresponding resistivity anomaly does not saturate in the temperature range studied.