Although mass screening for cervical cancer has been operational for more than 2 decades in the Netherlands, 700 women are still diagnosed with this cancer each year (9 per 100,000). We investigated these cases, in order to evaluate opportunities to further increase the effectiveness of the programme. We analyzed the screening history of women diagnosed with cervical cancer between 1994-1997 using the Dutch national pathology file that includes cervical cytology and histological results. More than half of the cases did not have previous preventive cervical smears, and another 30% had never been invited to the programme because of their age. In the future, we estimate that two thirds of all Dutch women with invasive cervical cancer will be unscreened or under-screened, based on current screening participation of more than 70%. We conclude that increasing screening participation has much more potential for further reducing cervical cancer incidence than reducing the screening interval, increasing the age range or having a screening test with higher sensitivity.