A prospective postal questionnaire study aimed to identify variables that predict a woman's intention to attend and her subsequent attendance/default at colposcopy clinics. One thousand two hundred and fifty-eight women attending colposcopy clinics of a university hospital were sent a postal questionnaire 3 weeks before their second appointment at colposcopy. An intention to attend the colposcopy clinic was the most significant predictor for colposcopy attendance during the next 15 months. Smoking and a longer travel time were associated with default. Our study shows that while interventions tried by service providers can reduce default rates, there will remain a cohort of women who do not fully participate in the screening programme.