After an organised cervical screening programme was introduced in Turin in 1992, the age-adjusted cervical cancer incidence ratio in 1992-98 was 0.81 (95% confidence interval (CI) 0.59-1.09) for invited vs not invited women and 0.25 (95% CI 0.13-0.50) for attenders vs non attenders. An organised screening programme can further reduce cervical cancer incidence in an area where substantial spontaneous activity was previously present.