Although several studies to evaluate the correlates between seroprevalence of herpes simplex virus type 2 (HSV-2) and sexual practices have been carried out with specific groups in Mexico, none has evaluated overall seroprevalence among the general population or its relationship with socio-demographic characteristics. The National Health Survey performed during 2000 in Mexico studied a multi-stage, stratified, cluster sample of the general population. Characteristics of the adult population, such as age, formal education, marital status, residence, age at first intercourse and categories of HSV-2 seroprevalence distribution by state, were studied. Specific antibodies against HSV-2 were determined by ELISA. The weighted seroprevalence of HSV-2 was 17.3% (95% CI 15.8-18.8) and showed significant variations according to age, sex, marital status, residence, age at first intercourse and categories of HSV-2 seroprevalence distributed by state. In conclusion, the prevalence of HSV-2 varied significantly according to the socio-demographic and geographic characteristics of the adult population in Mexico. These results suggest that variations in HSV-2 seroprevalence could be related to socio-economic and sexual behavior characteristics of the population. However, to support these assertions, further work could focus on the study of sexual behavior and its relation with the socio-economic distribution of the population in Mexico.