Screening with the faecal occult blood test (FOBT) has been shown in randomized control trials to be effective in reducing mortality from colorectal cancer. Compliance to this test recommendation, however, by the general population is usually low. To evaluate different methods of increasing compliance with FOBT, using mailed test kits or order cards, with or without information leaflets, subjects were randomly assigned to receive a test kit or a kit request card. An information leaflet was included in half of the mailings. All participants were contacted for interview. Compliance was evaluated through the central computer system of the study's FOBT laboratory. Self-initiated compliance with FOBT in the year preceding the study was 0.6% of the study participants. The overall compliance rate with the programme invitation was 17.9%, with a somewhat higher, though non-significant response to the mailed kit (19.9%) over the kit request card (15.9%). Women complied with the test significantly more than men, older participants more than younger. Compliance to FOBT is low among the Israeli population aged 50-74 who receive a formal invitation to carry out this screening. Mailing a kit request card within the framework of a screening programme can achieve a substantial increase (to 17.9%) in the level of compliance for the relatively low cost of postage. More effort is needed to study additional means of convincing the non-responders to take part in this potentially life saving activity.