Kaposi's sarcoma-associated herpesvirus (KSHV), the causative agent of Kaposi's sarcoma is able to infect several cell types. By investigating hyperplastic lymph nodes from AIDS patients with multicentric Castleman's disease, we demonstrate, for the first time, by dual colour immunohistochemistry, that KSHV is frequently detectable in germinal centre macrophages. These macrophages, which display a latency programme and frequently contain apoptotic bodies, may represent a non-negligible reservoir for the virus in lymphoid organs.