Background. The opportunistic basis on which screening has been conduc
ted in South Africa has resulted in multiple rescreening of a small pr
oportion of the population (which excludes most women at high risk) an
d low population coverage. There has consequently been a failure of sc
reening to impact on the incidence of cervical cancer in most of the p
opulation. Aim. To propose the use of the ratio of smears showing cerv
ical intra-epithelial neoplasia (CIN) III :smears showing signs of mal
ignancy as an indicator for the surveillance of equity in cervical cyt
ology screening, and to apply this indicator to an area of the Western
Cape of South Africa. Results. Marked inequity in screening is demons
trated between metropolitan and non-metropolitan areas, and between di
fferent non-metropolitan districts. Inequity in screening between diff
erent age groups of women is also found, and this is associated with a
n inappropriately young age distribution of screening activity. Conclu
sion. The application of this indicator in the routine surveillance of
screening activity may be useful in monitoring progress towards the i
mplementation of more equitable screening programmes, and the validity
of the indicator should be tested in other settings.