Killian-Jamieson diverticulum is a permanent protrusion of anterolateral proximal esophagus through anatomically weak muscular gap, known as Killian-Jamieson area, into adjacent area. During a routine educational dissection, we found a well-defined lateral diverticulum just inferior to the transverse fibers of the cricopharyngeus muscle in a Korean male cadaver. It had a dimension of 1.8×1.4×1.0 cm with two types of epithelial cells, stratified squamous and simple cuboidal to low-columnar epithelium, and attenuated and haphazardly arranged muscle fibers. No epithelial dysplasia or malignant transformation was identified except ulcerative changes. Although Killian-Jamieson diverticulum is a very rare disease, clinicopathological aspects should be considered.