Varicella-zoster virus (VZV) reactivation without cutaneous vesicles (zoster sine herpete) has been demonstrated in 8 to 25% of patients with acute peripheral facial palsy (APFP) by serological methods. To make an early diagnosis of zoster sine herpete, VZV DNA in oropharyngeal swabs from patients with APFP was examined by the polymerase chain reaction (PCR). VZV DNA was detected in oropharyngeal swabs from 6 of 36 (17%) patients with APFP by PCR. VZV DNA was detected in the oropharyngeal swabs from the six patients at their initial visit (2 to 4 days after the onset of APFP), while the anti-VZV IgM and IgG antibody titers were not increased significantly. In contrast, VZV DNA was undetectable in the oropharyngeal swabs at the time when the VZV specific antibody response appeared. These results indicate that detection of VZV DNA in oropharyngeal swabs by PCR is more useful than currently available serological assays for the early diagnosis of zoster sine herpete in patients with APFP.