The present invention relates to a water-gas shift process which is carried out in a non-aqueous, high boiling liquid medium, either in an ebullated or slurry mode. The function of the liquid is to provide a heat sink for the exothermic reaction thereby allowing for better performance and longer catalyst life. The process, termed "liquid phase shift" (LPS) preferably uses commercially available vapor-phase low temperature shift (LTS) catalysts to accomplish the shift reaction. Because of the isothermality of the LPS process and its ability therefore to take advantage of higher catalyst activity, the average operating temperature is typically 260oC (500oF). This compares favorably to the lower average operating temperature for the conventional vapor-phase LTS process, which is typically 240oC (465oF). In addition, the LPS process can handle high carbon monoxide content feeds, e.g. 75 vol% carbon monoxide on a dry basis, without experiencing excessive catalyst deactivation. High carbon monoxide content feeds cannot be handled by convention LTS processing.