A consideration of the consequences of human exposure to hexavalent Cr in the drinking water has been compiled. Since there is an absence of adequate human data on this subject the problem has been analyzed not only from human and animal studies but also from a mechanistic point of view. This treatise has been inspired by recent reviews and speculations that suggest that we may safely drink hexavalent Cr in great excess of the current EPA and states drinking water standards of 50-100 ppb.