Among 103 girls between the ages of 1 year and the prepubertal period, who came to autopsy, the incidence of columnar epithelium on the ectocervix was 42.7%. The extent of this change was mostly small, exceeding 30% of the length of the ectocervix in only 9 subjects. In some girls, only areas of squamous metaplasia or residual columnar structures (glands, channels, nabothian cysts) were present. The diagnosis of columnar epithelium in photographs at low magnification or by colposcopy is least exact among older girls. Such diagnostic difficulties appear to be related mainly to the small extent of columnar epithelium and to the diminished structural difference between areas of the original squamous epithelium and the columnar epithelium on the ectocervix.