Objective To investigate the value of colonoscopy with narrow band imaging (NBI) in predicting the histology of colorectal polypoid lesions. Methods A total of 173 colorectal polypoid lesions from 125 patients were included in the study. The lesions were diagnosed as neoplastic (adenoma or cancer)or non-neoplastic based on pit patterns and/or capillary patterns (CP), which was compared with the results of pathology, and the sensitivity, specificity and accuracy of each method were evaluated. Results In differentiation between neoplastic and non-neoplastic lesions, the sensitivity, specificity and accuracy of CP (94. 83% , 91. 23% and 93.64% , respectively), and those of CP combined with pit patterns (95. 69% ,96.49% and 95. 59% , respectively) were significantly higher than those of conventional colonoscopy (80. 17% , 84.21% and 81.50% , respectively, P<0.05). In differentiation between adenoma and cancer,the sensitivity, specificity and accuracy of CP were 86.90% , 100.00% and 87.93% , respectively.Conclusion NBI is superior to conventional colonoscopy in differentiation between neoplastic and non-neoplastic lesions, as well as in differentiation between adenoma and carcinoma.