We report a 41-year-old man with HIV and a chronic obstructive pulmonary disease, treated for seven months with Fluticasone/Salmeterol and antiretroviral therapy (Lamivudine, Tenofovir, Atazanavir and Ritonavir). While using these medications, the patients developed a Cushing syndrome in a period of five months. After performing laboratory and imaging tests, it was concluded that the most probable cause of the syndrome was the interaction of inhaled steroids with Ritonavir. After discontinuing these medications the syndrome reverted in a period of 8 months.