Cancer of the uterine cervix is a global problem. It is the most common cancer in women in developing countries and is the second most common cancer in women worldwide, with approximately half a million new cases each year. It is strongly linked with an early onset of sexual activity and multiple sexual partners; recent evidence points to a causal link between some of the precursor lesions of this cancer and specific papillomavirus infections. Cervical cancer has significant morbidity and mortality if it is not detected before it reaches an advanced stage with symptoms. If the disease is detected in an early asymptomatic stage it is nearly always curable by surgery or radiotherapy. Therefore today, cytological screening is the mainstay for control of cervical cancer.In some developed countries, screening programmes for cervical carcinoma have been in operation for many years. In places where large well-organized programmes have been functioning, significant decreases in mortality, in the range of 50-60%, have been observed. The favourable effects result primarily from the removal of intraepithelial lesions preventing the occurrence of invasive tumours.In countries where resources are limited, the aim should be to screen every woman once in her lifetime between 35 and 40 years of age. When more resources are available the frequency of screening should be increased to once every ten or five years for the age groups 35 to 55 years and, ideally, once every three years for women aged between 25 and 60 years.