The colposcopic findings in 86 virgin teenagers are reported and compared with a matched control group of 172 sexually active teenagers. The results show that an atypical transformation zone may be observed in virgins and that the prevalence rate of this condition is different when compared with that of sexually active teenagers. These data suggest that: 1) the presence of a colposcopically observed atypical epithelium is due to a normal maturation process occurring in young women after the menarche, and 2) coitus is responsible for the prolongation of this process in sexually active teenagers.