This statement summarizes the U.S. Preventive Services Task Force (USPSTF) recommendation and supporting scientific evidence on routine use of aspirin or nonsteroidal anti-inflammatory drugs for the primary prevention of colorectal cancer. The complete information on which this statement is based, including evidence tables and references, is available in the accompanying articles in this issue and on the USPSTF Web site (http://www.preventiveservices.ahrq.gov). The USPSTF is redesigning its recommendation statement in response to feedback from primary care clinicians. The USPSTF plans to release, later in 2007, a new, updated recommendation statement that is easier to read and incorporates advances in USPSTF methodology. The recommendation statement below is an interim version that combines existing language and elements with a new format. Although the definitions of grades remain the same, other elements have been revised.