Opportunistic infection with the causative agent of cat scratch disease may be responsible for an unusual vascular proliferative lesion, referred to as bacillary epithelioid angiomatosis, previously described only in human immunodeficiency virus (HIV)-infected patients. We present a case of an HIV-infected patient with bacillary epithelioid angiomatosis involving the liver and bone marrow causing progressive hepatic failure. We also report a case of a cardiac transplant recipient with hepatic and splenic bacillary epithelioid angiomatosis manifesting as a fever of unknown origin, a previously unreported event in a non-HIV-infected patient. These cases represent the first documentation of bacillary epithelioid angiomatosis with visualization of cat scratch-like organisms involving internal organs.