Measurements of the activities of enzymes unique to the pentose phosphate pathway of glucose metabolism were made in rat gingival homogenates. The results established that gingiva contains the complete complex of enzymes unique to the pentose phosphate pathway. The studies showed that the oxidative enzymes of the pentose phosphate pathway are present in gingiva in greater concentrations than the non-oxidative enzymes of this pathway. Specific activities are given for rat gingival glucose 6-phosphate dehydrogenase, 6-phosphogluconic dehydrogenase, ribose 5-phosphate isomerase, transketolase and transaldolase. The rates of 14CO 2 formation from glucose-1- 14C and glucose-6- 14C during in vitro incubations with normal rat gingiva were determined. The rate of 14CO 2 formation from glucose-1- 14C was consistently greater than that from glucose-6- 14C. These data are discussed in regard to the function of the pentose phosphate pathway in gingival glucose metabolism.