Cervical scrapings from 78 women attending a sexually transmitted diseases (STD) clinic, family planning clinic, and colposcopy clinic were assayed for human papillomavirus type 6 (HPV-6) by DNA hybridisation. Results of hybridisation were compared with clinical, colposcopic, and cytological findings. Scrapings from 2 of the 4 women with genital warts gave positive results with the HPV probe. No HPV-6 DNA was detected in scrapings from 18 women attending an FPC whereas scrapings from 2 of 19 STD clinic patients with normal colposcopic and cytological examination were positive-this means that DNA hybridisation detected wart virus infection where previously none was suspected. HPV-6 DNA was detected in about 10% of cervical scrapings from women with cervical intraepithelial neoplasia (CIN) both before and after treatment. Indeed in 2 patients in whom viral DNA persisted after laser therapy, it was associated with local recurrence of neoplasia. This non-invasive technique is suitable for use as a screening test for HPV infection. In this study it identified women who have a high risk of developing CIN and in whom close cytological and colposcopic surveillance is indicated.