Pulmonary arterial hypertension [PAH] is a rare but well-known cardiovascular condition potentially associated with human immunodeficiency virus [HIV] infection and is currently recognized to be one of the most ominous noninfectious HIV complications. Although there is no clear evidence supporting the use of any medication for the treatment of HIV-related PAH, many of the currently available agents have been shown to exert some clinical benefits HIV-PAH patients. To date, no data are available regarding the potential effects of sitaxsentan, a selective endothelin type-A receptor antagonist, in this peculiar patient population. We report the case of a successful switch to sitaxsentan in a HIV-infected patient with PAH initially receiving bosentan who developed a late treatment-related side-effect.