Background: Recently, esophageal microcancers have been frequently diagnosed and are receiving increasing attention as initial findings of cancer. We examined whether the clinicopathological features and microvascular patterns of esophageal microcancers on magnifying endoscopy are useful for diagnosis. Methods: Magnifying endoscopy was performed to examine the histopathological features of 55 esophageal cancers measuring <= 10 mm in diameter (34 small cancers, 16 microcancers, and five supermicrocancers). Results: Although some lesions were detected only on iodine staining, most were detected on conventional endoscopic examination. Most small cancers and microcancers were m1 or m2; some were m3 or sm2. Supermicrocancers were dysplasia or m1. cancer. As for the microvascular pattern, most m1 and m2 cancers showed type 3 vessels, while most submucosal cancers showed type 4 vessels. Conclusions: Microvascular patterns on magnifying endoscopy are useful for the differential diagnosis of benign and malignant esophageal cancers and for estimating the depth of tumor invasion. The shape of small lesions is often altered considerably by biopsy. Residual tumor may persist unless the basal layer of the lesion is included in biopsy specimens, even in microcancers. Consequently, endoscopic mucosal resection, without biopsy, is being performed in increasing numbers of patients with lesions suspected to be cancer on the basis of their microvascular patterns.