Human herpesvirus 8 (HHV8), which has been suggested as the causal agent of Kaposi's sarcoma (KS), has also been implicated in the pathogenesis of sarcoidosis. We describe a patient affected concomitantly by sarcoidosis and KS. HHV8 sequences were detected with PCR only on KS lesions, whereas sarcoid tissues did not harbor HHV8 DNA. Immune dysfunction related to sarcoidosis may have facilitated the oncogenic role of HHV8 and the development of KS.