Background: The aim of this study was to evaluate the characteristics of advanced colorectal neoplasias in asymptomatic subjects with positive fecal immunochemical test(fiT) Methods: A total of 378 subjects who have undergone colonoscopy were enrolled as fiT positive group. In addition, a total of 378, age-sex matched subjects with negative fiT who have undergone colonoscopy were recruited as well as a control group. Results: Among a total of 756 subjects, 350 subjects had one or more adenomas. On per polyp analysis, a total of 783 colorectal neoplasias were found in both group (448 in fiT (-) vs. 335 in fiT (+), p=0.022). Cancers, HAA and large adenomas more than 10 mm in size were more frequently found in fiT positive group (figure 1). Interestingly, among adenomas more than 10 mm in size, adenomas with advanced histology including HGD or cancer were equally found in both groups (41.4% in fiT (-) vs. 48.9% in fiT (+), p=0.527). However, adenomas less than 9 mm in size with advanced histology including HGD or cancer were signifi cantly more frequent in fiT positive group than those in fiT negative group (7.6% vs. 0.7%, p<0.001, respectively). The site specifi c performance of fiT (right vs. left) for detecting AAs was not different between both groups (p=0.079). Conclusions: Compared to those with fiT negative, asymptomatic subjects with fiT positive on colorectal cancer screening showed similar non-advanced adenomas but higher advanced histologies even a small sized lesion. These results suggest the necessity of more rapid and complete resection for lesion found in asymptomatic subjects with fiT positive lesion. This study was supported by a grant from the National R&D Program for Cancer