A spectrum of noninfectious, nonmalignant lymphocytic infiltrative disorders, including nonspecific interstitial pneumonitis and lymphocytic interstitial pneumonitis, was frequently described in HIV-infected adults in the precombination antiretroviral therapy (ART) era. With the advent of ART, these conditions are less commonly encountered when caring for HIV-infected adults, possibly as a consequence of the effects of HIV treatment on pulmonary immunology. By contrast, reports of sarcoidosis among HIV-infected persons were uncommon in the pre-ART era, but sarcoidosis is increasingly recognized since the introduction of ART and may represent an immune reconstitution phenomenon. Other causes of interstitial pneumonitis are infrequently encountered among HIV-infected persons.