The greatest utility of sentinel lymph node (SLN) assessment is the avoidance of lymph node dissection and related morbidity. Another potential utility is the ability to direct pathologic examination and more sensitive techniques to detect occult micrometastatic disease. New pathologic methods can identify single tumor cells or even genetic material within a single lymph node station, bringing the concept of ultrastaging and micrometastasis in the field on staging. This article describes the SLN technique in patients with early non–small-cell lung cancer, as unique and useful targeting enables pathologists to localize micrometastatic foci within an otherwise normal lymph node.