This edition of Best Practice & Research, Clinical Obstetrics and Gynaecology focuses on Screening for Gynaecological Cancers and the evidence that it either prevents disease or enables early detection and hence increased opportunities for treatment and/or cure. The authors come from diverse regions and all have extensive experience in their fields. Cervical cancer prevention through national cytology based programmes is the most obvious example of successful screening, however, the impact on reduction of cervical cancer experienced in developed countries has never been translated into developing country or low-resource settings, where the greatest burden of cervical cancer is found. This is largely due to the complexity of the infrastructure and resources required, along with competing health needs in poor countries. This edition will explore the evaluation of alternatives to cytology-based programmes that have been studied in the past 15 years, including some of the first randomised trials of alternative screening tests with longitudinal follow up – all of which show extremely positive results in both developed and developing world contexts. The Health Economics of screening for gynaecological cancers is discussed in Chapter One which explores the key issues that affect cost-effectiveness of screening. These include disease burden and availability of and type of screening tests. The most useful data is found in cervical cancer, including an analysis of the likely impact of vaccination against high-risk types of Human Papillomavirus. There is also data on ovarian cancer prevention that allows for mathematical modelling of likely impact on morbidity and mortality. While screening per se is not performed for vulval disease, careful clinical assessment of the vulva in all women is advised, and long term follow up where appropriate. There is no evidence for mass screening for uterine cancers, however, at risk women and evidence based interventions are explored in Chapter 9. Similarly, with ovarian cancer a definitive reduction in mortality due to screening is yet to be convincingly demonstrated. Screening for gynaecological cancers in genetically predisposed women has definite value. Breast cancer screening, particularly in developing countries, is controversial yet recommended.