The characteristics of current flow through thermally and anodically grown oxides of vapor deposited and bulk InSb are reported. The magnitude of the current though the thermal and anodic oxides are found to be markedly different. The thermally grown oxides have very low resistance similar to In2O3. The anodic oxides are insulating and the current flow is characteristic of Schottky emission. The anodic oxides grown on bulk single crystals (BSC) and on thin films deposited at 150° and 350°C have essentially the same current−voltage characteristics. The breakdown strength of the BSC oxides is approximately 50% greater than of the thin film oxides.