OBJECTIVE This study looks at the Papanicolaou (Pap) smear histories of patients presenting with invasive cervical cancer, to assess the problems associated with the cervical cancer screening program within New South Wales. METHODS Prospective collection of data concerning the Pap smear history, age, menopausal status and stage of disease of patients presenting with invasive cervical cancer. METHODS All patients with primary invasive cervical cancer referred to the Gynaecological Oncology Department of the Royal Hospital for Women, Paddington, between November 1986 and July 1990 were included in the analysis. RESULTS Eighty-three out of 237 patients (35%) reported never having had a Pap smear taken. These patients were on average older, more frequently postmenopausal and presented with more advanced stage of disease than the rest of the population. Fifty-one patients (21.5%) stated that they had had a "normal" smear within two years. Further analysis revealed that mistaken patient recall of the date of the last Pap smear and false-negative cytological reporting were the major factors explaining these latter cases. CONCLUSIONS For voluntary screening to be more effective, quality control of cytology laboratories needs to be carefully evaluated and general practitioners need to take a more active role in cancer screening. In order to reach a greater proportion of the population, a national or State cytology register should be established.