Large amounts of metallic silver pigment were found in 10 cervical biopsy specimens taken for the histological grading of cervical intraepithelial neoplasia (CIN). The assessment of CIN was made much harder because the pigment obscured the morphological detail of the epithelial cells, and in some it was very difficult to determine whether koilocytosis or CIN I was present. The silver can easily be removed by a simple chemical method.