An infant with congenital absence of the nostrils, incomplete prolabium, incomplete premaxilla, nasal cavity without septum, and cleft palate is presented. To clarify the embryological development of the nostril, serial sections of many embryos and fetuses of various stages were examined. Recanalization of the nostril, resulting from resorption of the temporary nasal epithelial plug, was observed in a 13- to 15-week fetus. Although textbooks of human embryology describe its occurrence in the 6th month or 24th week of fetal life. This finding suggests that the embryological cause of congenital nostril atresia, in the present case, may have been persistence of the plug.