Glucocorticoid-induced glucose intolerance has been related to the dose, duration of treatment, and steroid compound. However, a clear demonstration of this phenomenon is still lacking for fluorinated corticosteroids. We performed an oral glucose tolerance test in six healthy volunteers after the short-term administration of deflazacort (18 + 18 mg), prednisone (15 + 15 mg), and betamethasone disodium phosphate (1.5 + 1.5 mg) at equivalent anti-inflammatory doses, in random sequence, and in a triple crossover design. Fasting plasma glucose levels were not modified by deflazacort, whereas fasting plasma glucose levels together with insulin and C-peptide values were progressively and significantly increased by prednisone and betamethasone. During oral glucose tolerance testing a significant increase in the plasma glucose and insulin peaks was recorded after betamethasone and, to a lesser extent, after prednisone and deflazacort. These results suggest that betamethasone induces greater glucose intolerance and insulin resistance than prednisone and deflazacort.