Ritonavir and atazanavir (ATZ) are protease inhibitors (PI) that inhibit the P450 3A4 cytochrome. They are used together to boost ATZ levels and reduce pill burden in human immunodeficiency virus infection, but association with medications metabolized by this cytochrome can cause serious adverse effects. Several cases of Cushing's syndrome have been reported when patients received inhaled therapy with fluticasone for asthma, sometimes complicated by secondary adrenal failure after stopping fluticasone. We report a case of Cushing's syndrome associated with onset of diabetes mellitus in a patient treated with boosted PI (ATZ and ritonavir) for HIV 2 (CD4360/ml). Asthma was treated with inhaled fluticasone 1500mug/day for several months that was stopped at admission. A few days later, typical secondary adrenal failure developed and was confirmed by dosage of cortisol and ACTH, both low. Hydrocortisone replacement treatment resulted in rapid improvement of symptoms. Diabetes was initially treated with insulin then sulfonyluraes, but repeated hypoglycemias lead to diet alone. Physicians should be aware of the potential danger of the association of "boosted" IP and some kind of inhaled corticotherapy.