Darunavir (DRV) is an HIV-1 protease inhibitor that is used together with a low boosting dose of ritonavir as part of an antiretroviral therapy (ART) regimen in treatment-experienced and naïve HIV-positive patients. In naïve and experienced patients with no DRV-mutations, DRV is licensed at the dose of 800 mg plus 100 mg of ritonavir once daily. We report our results in seven ART-experienced HIV-infected patients, in whom a reduced dose of darunavir/ritonavir (600/100 mg once daily) successfully controlled viral replication.