OBJECTIVE To evaluate the clinical value of magnifying endoscopy in diagnosis and treatment of colorectal benign neoplastic lesions. METHODS Seventy-eight colorectal lesions in 61 patients were examined with magnifying colonoscopy after indigo carmine dyeingìand pit pattern diagnosis was made for every lesion according to Kudos classification to differentiate neoplastic lesions from non-neoplastic lesions. The lesions were resected by endoscopic polypectomy and mucosectomy or surgical treatment. The diagnoses made by magnifying colonoscopy were compared with pathologic results. RESULTS The diagnostic sensitivity of magnifying endoscopy for neoplastic lesions was 98.4% and specificity was 85.7%. The overall accuracy for adenoma and early colorectal cancer was 96.2%. 89.7% of adenomatous lesions were treated by endoscopic resection. CONCLUSIONS The magnifying colonoscopy can provide instantaneous and accurate diagnosis of neoplastic lesions in colon and rectum,as well as minimally invasive treatment.