Research carried out by the authors at the University of Texas at Austin has shown that the wettability characteristics of consolidated sandstones have a pronounced effect on the electricalproperties they exhibit. Normal application of the Archie equation can lead to large errors in water saturation calculations if the wettability character of a rock and its saturation history are not taken into consideration. The Archie saturation exponent "n" has been found to vary from 1. 2 to 5. 2 depending on stress and wettability conditions. The saturation history of the core has a considerable effect on the saturation exponent, particularly in water-wet situations. Hysteresis effects are used to explain consistently differing values of "n" between drainage and imbibition. Changes in stress have a relatively minor effect upon the saturation exponent and the cementation exponent "m", but trends showing an increase in these exponents in response to increasing stress have been observed. Resistivity was monitored at 1 inch and 2 inch intervals along 6-inch cores in order to examinethe electrical and capillary end effects. Computerized Axial Tomography was used to observe the fluid distribution within the sandstone cores under different saturation conditions. The independent determination of fluid saturations through use of CAT scans allows the isolation of electrical end effects from saturation end effects. The results of our work have many implications on the analysis of electrical resistivity logs. The effects of varying wettability conditions around the wellbore and its influence on electrical log interpretation should be considered when electrical logs are analyzed. This is particularly true when analyzing RXO vs. Rt logs for moveable oil saturations. The invasion of surface active mud components can cause wettability reversal. The invasion of oxidizing drilling mud can also result in asphaltene deposition and thereby have a pronounced effect on the wettability character of the formation in the near wellbore region. These factors can cause the saturation exponent near the wellbore to be different than the saturation exponent away from the wellbore. This condition becomes important when estimating the moveable oil saturation from electrical resistivity logs.