Colorectal cancer is second only to lung cancer as a cause of death due to cancer in the united States. Studies have shown that fecal occult blood(FOB) tests are effective in detecting colorectal cancer in its early stages. To motivate worksite FOB testing, a randomized controlled trial was conducted. Employees 40 years or older from three federal agencies in Washington State were randomized to a control group(n=139) which received a letter stating the availability of the FOB test at the worksite clinic or to an intervention group(n=139) which received the letter about facts on colorectal cancer and a Colorectal Cancer Risk Appraisal. The Colorectal Cancer Risk Appraisal included a feedback on an individual's risk of developing colorectal cancer compared to his/her peers in terms of 'normal', 'moderate', or 'high' risk status. After 3 months, a follow-up questionnaire was sent to all participants to measure the effectiveness of the intervention. In the analysis of the three major outcomes, two possible confounding factors(dietary fat and family history of colorectal cancer) were controlled by logistic regression. Based on a review of the worksite clinic records, the intervention group had 4.3% higher compliance rate with the FOB test during the follow-up period compared to the control group(p=.10). The largest effect of the intervention was on the employees' intention to get a FOB test within the next year(62.6% in the intervention group vs. 36.2% in the control group, OR=3.18, p<.001). In the final Multivariate logistic model, the employees who were more likely to intend to get a FOB test within the next year were in the intervention group ; were at 'moderate' or 'high' risk of colorectal cancer ; knew more about the availability of the FOB test at the worksite clinic ; and had a FOB test during the last tree years.