Present methods of assessing pulp vitality (electric and thermal testing) are of limited use with children, often resulting in false positive or false negative results. Pulse oximetry is a proven, atraumatic method of measuring vascular health by evaluating oxygen saturation (SaO2). This pilot study explores the use of a modified pulse oximetry ear probe to assess pulpal vascular oxygen saturation in primary and immature permanent teeth. Pulse oximetry readily differentiated between known vital and nonvital teeth. Vital teeth consistently provided SaO2 values that were lower than the values recorded on the patients' fingers. Further study of the SaO2 changes in traumatized teeth, with a probe designed specifically for teeth, is warranted by these initial results. Although additional research is indicated, pulse oximetry is already an objective, atraumatic clinical alternative to the present electrical and thermal methods of assessing pulp vitality in children's teeth.