The use of high salinity and sodicity irrigation water is increasing due to the competition for limited supplies of good-quality water. The objective of this research was to evaluate the influence of high sodium adsorption ratio (SAR) on the bulk soil electrical conductivity (EC_a) of three soils with smectite, vermiculite-smectite, and kaolinite as predominant clay minerals. Samples of the three soils were moderately sodificated by leaching with three pore volumes of NaCl-CaCl₂ solutions (incipient sodification). The EC of the leaching solution ranged from <0.01 to 20 dS m^-1 and SAR from 0 to 50. A separate procedure was conducted on smectitic soil samples, which were equilibrated with solutions of decreasing EC (from 40.0 to 3.0 dS m^-1) and SAR 50 and 0 (complete sodification). For incipient sodification, SAR had no significant effect on the EC_a of any of the test soils. The EC_a of the kaolinitic soil was consistently lower than the EC_a of the smectitic and vermiculitic soils. For complete sodification, the EC_a of the smectitic soil increased from 1.14 to 2.42 dS m^-1 when SAR increased from 0 to 50, provided that the EC of the soil solution (EC_w) was ≤ 4 dS m^-1. This response was attributed to a 46% increase in water content on the series path and 58% increase in EC of the solid phase when SAR increased from 0 to 50. For EC_w beyond 4 dS m^-1, the difference in EC_a between SAR 0 and SAR 50 treatments diminished progressively. For both the smectitic and vermiculitic soils, SAR ≤ 13 does not affect the relationship between EC_a and EC_w. The EC_a of the smetitic soil increases when SAR is 50 and EC_w is ≈4 dS m^-1.