OBJECTIVE: Colorectal Cancer (CRC), when detected early, can be treated, reducing morbidity and mortality. In 1997, the American Cancer Society issued major revisions for CRC screening guidelines to include new research findings and improvements in testing accuracy. Research suggests that physicians do not always follow CRC screening guidelines; lack of knowledge about appropriate guidelines or guideline changes is often cited as a barrier. The aim of this systematic review was to examine studies measuring physician CRC screening knowledge and related practice patterns. METHODS: A tiered systematic search (1997-2004) was conducted for studies, irrespective of design, which were published in peer-reviewed journals through MEDLINE, Academic Search Elite, CancerLit, CINAHL, and PsycINFO databases. Tier 1 search combined keywords “knowledge” and “physicians” with “colorectal cancer screening” which identified 48 studies. Tier 2 search combined keywords “practice patterns” and “physicians” with “colorectal cancer screening” which identified 52 studies. Tier 3 was a review of papers identified in Tiers 1 and 2. Ten studies meeting the “knowledge” and “practice patterns” inclusion criteria were retained. RESULTS: Studies reported that a significant percentage of physicians were performing Fecal Occult Blood Test on stool samples obtained from Digital Rectal Examination, a method that often produces false results. Roughly half of physicians were reported to be performing screening tests without adequate patient preparation in terms of dietary restrictions which could impede test accuracy. There were inconsistencies among physicians regarding when in a patient's life to initiate screening, and at what age to discontinue screening. CONCLUSIONS: This systematic review of ten included studies reflected considerable knowledge gaps among physicians, which could contribute to reasons for inadequate screening rates. Provider education about CRC screening should emphasize guidelines regarding when to start screening, frequency rates for screening with given modalities, and particular techniques and precautions that should be used to perform screening.