The oxidative metabolism of Rhodolorula gracilis NRRL Y-1091 was investigated. Data was presented showing the oxidation of glucose, acetate, pyruvate, xylose, D- and L-arabinose, by both glucose- and xylose-grown cells. Gluconate was oxidized by the glucose-grown cells, while ribose was oxidized by the xylose-grown cells. Cell-free extracts of glucose-grown cells oxidized glucose, gluconate, glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-diphosphate, and ribose-5-phosphate. Pentose phosphate was demonstrated as a product of glucose-6-phosphate oxidation. Resting-cell suspensions were unable to oxidize citrate, but they oxidized the dicarboxylic acids of the TCA cycle. Citrate was detected as a product of the oxidation of acetate, pyruvate, and malate in the presence of fluoroacetate. Cell-free extracts of glucose-grown cells oxidized citrate, isocitrate, and the dicarboxylic acids of the TCA cycle.