The stroma often fibroepithelial and ten adenomatous cervical polyps, 12 fibro-epithelial vaginal polyps, 20 non neoplastic cervices, 15 cone specimens with CIN changes and five specimens with infiltrative squamous cell carcinoma was investigated. Vimentin, desmin, actin, collagen III, CD34, ER and PgR were studied using the Ventana Automatic Immunostaining System. A subepithelial stromal layer was detected in 17/20 normal specimens, 16/20 cervical polyps, 10/12 vaginal polyps and in 6/15 cone biopsies but not in neoplastic specimens. Vimentin staining was positive in all fibroepithelial polyps, normal specimens and in 6/10 adenomatous polyps. Actin was negative in the loose subepithelial zone but positive in the underlying stroma. Desmin, alpha-1-antitrypsin and CD34 were detected in isolated cells in normal specimens. ER and PgR were observed in isolated subepithelial cells, with greater density in the cells of the fibromuscular wall. In conclusion, loose mesenchymal stroma in the lower female genital tract of a fibrohistiocytic nature was observed with minimal smooth muscle participation--which is the matrix of vaginal and cervical polyps.