Background-Women once treated for high grade cervical dysplasia have a high long term risk for developing new dysplasia or cancer.Objectives-To investigate if human papilloma virus (HPV)-negativity after treatment of cervical dysplasia reduces the need for frequent long term follow up.Design-Case/control study based on archival smears.Methods-Women with cervical intraepithelial neoplasi (CIN)2-3, treated for dysplasia and with recurrence of CIN2+ more than 2 years after treatment were compared with controls without recurrence, matched for age and date of treatment. High risk-HPV-DNA were analysed with PCR from two archival smears per woman. Mean follow up time was 14.6 years.Results-24% (45/189) of cases and 11% (43/378) of controls were HPV-positive in any of two smears. Odds ratio (OR) = 2.5 (1.6-3.8).Conclusion-HPV-status 6-12 months after treatment of high grade dysplasia is of limited value for the design of long term follow up.