OBJECTIVE: This study was designed to investigate the value of serologic examination in the diagnosis of childhood herpes simplexvirus (HSV) infection. METHODS: Serum samples were collected from 2 436 outpatients and inpatients. The samples were divided into two groups. Group 1 consisted of 321 samples which were assayed for HSV-1 IgG, HSV-1 IgM, HSV-2 IgG or HSV-2 IgM antibody using herpes simplex virus antibody kits between January 2003 and November 2005. Group 2 consisted of 2 115 samples which were assayed for HSV-2 IgG and IgM antibodies by TORCH testing between October 2004 and November 2005. RESULTS: In Group 1, the total seroprevalence of HSV infection was 44.6%, with 38.9% being HSV-1 positive and 15.9% HSV-2 positive; HSV-IgM positivity was found in 41.1% and 25.5% were HSV-IgG positive; HSV-1 seroprevalence significantly increased with age (P <0.05). In Group 2 the seroprevalence of HSV-2 infection was 1.9%; all of the samples were HSV-2 IgG positive. CONCLUSIONS: HSV serologic examination is useful in the diagnosis of HSV infection in children.