Colorectal cancer is a major cause of morbidity and mortality in the United States. Despite the availability of methods for early detection of this cancer, compliance with published screening guidelines is poor. We began a study using a pretest/posttest design to determine the effectiveness of several methods of improving colorectal cancer screening in an internal medicine residents' Veterans' Administration (VA) Primary Care Clinic. The interventions varied by day of the week and included (1) distributing self-administered Hemoccult II slide kits to patients at clinic registration; (2) conducting an education session for house staff on colorectal cancer screening; and (3) placing reminder cards on patients' medical records. Preintervention rates of compliance with age-related screening guidelines recorded in the medical record within the past year were digital rectal examination, 70%; one-time fecal occult blood test, 59%; three-day fecal occult blood test, 1%; and screening sigmoidoscopy (at any time in the past), 5%. No change in physician-performed examinations was seen in any group approximately six weeks after the interventions. However, systematic distribution of Hemoccult II kits resulted in a dramatic increase in screening through this method, to 56.8% (P less than .001). In this setting, physician education and reminders may be insufficient to improve colorectal cancer screening. We discuss possible explanations for this finding, including the high preintervention screening levels and the perception of an already overburdened system. Patient involvement in screening and mechanisms built into the clinic operation may be more successful.