Darunavir boosted by low-dose ritonavir (DRV/r), at a daily dose of 600/100 mg twice a day (bid), has been shown to be superior to alternative highly active antiretroviral therapy (HAART) regimens for the management of treatment-experienced, HIV-infected adults in the phase IIb POWER trials and the phase III TITAN trial. Economic analyses of different types that have been performed for several countries to investigate the cost effectiveness and budgetary impact of DRV/r 600/100 mg bid for treatment-experienced people living with HIV (PLHIV) based on the clinical data gathered in the POWER and TITAN trials are reviewed for consistency and their value to different decision-makers is assessed. Cost-utility analyses for the USA and several European countries indicate that DRV/r-based HAART is cost effective compared with other standard of care protease inhibitor (PI)-based regimens in PLHIV with evidence of PI resistance. For all of these countries, the estimated cost-utility ratio is well below typical benchmark values and these ratios are robust, as demonstrated by one-way sensitivity and variability analyses and multi-way probabilistic sensitivity analyses. Studies using other metrics including the average 1-year drug cost per patient with a plasma HIV-RNA level less than 50 copies/mL at 48 weeks, the incremental drug cost per additional patient with a plasma HIV-RNA level less than 50 copies/mL at 48 weeks, the total (antiretroviral and non-antiretroviral) costs during the first year of treatment, and the total healthcare budget impact during the first 5 years of treatment provided further evidence of the positive economic outcomes with the use of DRV/r in treatment-experienced PLHIV. Different measures of economic outcomes are useful for different types of decision-makers and different types of decisions. In general, the results of these different types of analyses will be consistent with each other. For darunavir, the economic analyses reviewed in this paper demonstrate that the use of DRV/r 600/100 mg bid in the management of HIV-infected, treatment-experienced adults who have failed at least one of the other currently available PIs is cost effective and may be cost saving.