Background. Neonatal herpes simplex virus (HSV) is a serious, life-threatening infection that is usually acquired during birth from contact with infected maternal genital secretions. Primary maternal HSV gingivostomatitis is a rare occurrence during pregnancy, and HSV type 1 (HSV-1) neonatal disease after primary maternal HSV gingivostomatitis during pregnancy has not been reported in detail. Methods. We reviewed the medical records of neonates (28 days of age) with a confirmed diagnosis of neonatal HSV-1 at a single pediatric center from January 1981 to January 2010 to identify cases in which the mother had primary gingivostomatitis during pregnancy or at term. Results. Seven neonates whose mothers had primary HSV-1 gingivostomatitis during pregnancy were identified from a review of 48 neonates with laboratory-proven HSV-1 neonatal disease. Of the 7 women, 2 presented with symptoms of primary HSV-1 gingivostomatitis during the first trimester and 5 in the third trimester. Three of the neonates developed skin, eye, and mucous membrane disease, 2 developed central nervous system disease, and 2 developed disseminated disease. One of the neonates with disseminated HSV-1 disease died. Conclusions. Primary maternal HSV gingivostomatitis during pregnancy may lead to HSV-1 transmission to the neonate. Physicians caring for pregnant women should communicate the diagnosis of HSV gingivostomatitis to the neonate's primary provider to ensure proper surveillance, early evaluation, and prompt treatment.