Aim: To assess and validate the diagnostic value of buccal and vaginal smears in the ambulatory care of girls with potential disorders of puberty. Methods: Smears were obtained from 77 girls who presented for assessment of their pubertal status, stained as described by Papanicolaou, examined for signs of estrogenization according to the method of Schmitt, and compared with the clinical status. Results: Vaginal but not buccal smears reflect accurately the changes of sexual maturation, even more sensitive than single serum hormone measurements. Conclusions: Vaginal smears represent a valid, reproducible, and well-tolerated diagnostic tool in the ambulatory care of peripubertal girls to identify their estrogen status with high sensitivity and specificity. The decision to perform confirmative but invasive diagnostic procedures can be based on auxology, physical examination, bone age determination, and analysis of vaginal smears.