INTRODUCTION: Age, gender and indication for the examination are known predictors of adenomatous polyp detection during colonoscopy. But no one knows the importance of the endoscopist in detection. OBJECTIVES: To determine the role of the endoscopist in detecting adenomatous polyps during colonoscopy MATERIAL AND METHODS: Is retrospective cross-sectional correlational study. Data were recorded colonoscopies performed in the Japanese Peruvian Polyclinic during 2007, which were conducted by 10 endoscopists RESULTS: A total of 843 colonoscopies. Statistical analysis showed significant differences between endoscopists regarding the detection rate of adenomatous polyps (p = 0.038). The range for the detection of at least 1 adenomatous polyp by colonoscopy was 14,6-30,0%. In patients over 50 years, there were also significant differences between endoscopists in detection rate of adenomatous polyps (p = 0.001). The range for the detection of at least 1 adenomatous polyp was 18,2-37,5% in that group.Also found that age and gender were powerful predictors of adenomatous polyps, both for the total cohort, and patients older than 50 years. Regarding the indication for colonoscopy, no significant difference between the categories, were found p = 0.288 CONCLUSION S: The endoscopist is as or more important than age, gender or indication for the examination, in predicting the detection of adenomatous polyps during colonoscopy.