BACKGROUND The English National Health Service Cervical Screening Programme (NHSCSP) recommendation not to offer cervical screening to women aged 20-24 years is considered in the context of national rates of cervical intraepithelial neoplasia grade 3 (CIN3) and invasive cervical carcinoma, falling screening coverage in young women, detection of screen-detected invasive cancers and risks of excisional treatment of CIN. METHODS Registrations of invasive and in situ cervical carcinoma were obtained from the Office for National Statistics, data on screening coverage and cytology results from the NHSCSP website and data on screen-detected cancers from an audit at Guy's & St Thomas' NHS Foundation Trust (GSTFT). RESULTS Before and after the introduction of organised screening in England, CIN3 was primarily detected in women aged 20-39 years. Increasing rates of CIN3 were recorded in women aged 20-24 years during the last decade (3000-4000 cases per year) despite falling screening coverage. The peak incidence of invasive cancer in screening age groups is now 35-39 years. At GSTFT in 1999-2006, 24 of 32 cancers (75%) in women aged 20-34 years were screen-detected and that percentage declined in subsequent 15-year age bands (p < or =0.0001). CONCLUSIONS Delaying the age for screening eligibility carries a risk of CIN becoming more extensive, and therefore more difficult to excise, as well as a risk of progression. The NHSCSP should reconsider its decision and encourage young women to be screened, not excluding those aged 20-24 years. Facilities for taking the tests should be made more convenient. Women should be informed that low-grade CIN is potentially reversible and may safely be monitored. Cervical screening also provides an opportunity for education on healthy lifestyles and safer sex while treatment should be reserved for high-grade CIN.