We examined the cervical lymph nodes of 30 patients with Kikuchi's disease and 15 patients with nonspecific lymphadenitis, using Southern blot analysis and polymerase chain reaction (PCR) to identify human herpesviruses such as Epstein-Barr virus (EBV), cytomegalovirus, herpes simplex virus, and varicella-zoster virus. By Southern blot analysis, no virus DNA was recognized, but 16 of the 30 nodes from patients with Kikuchi's disease and 8 of the 15 nodes from patients with non-specific lymphadenitis showed amplified EBV DNA by PCR.