Although modern imaging techniques become more accurate for the assessment of lymph node metastases in the neck as criteria and technology evolve, micrometastases remain occult with any technique. Even the routine histopathological examination of neck dissection specimens is unable to detect all micrometastases. Because knowledge on the incidence of micrometastases in the clinically NO neck might be of importance for decision making regarding elective treatment, a retrospective study on 96 elective neck dissections was conducted. Meticulous histopathological examination of the neck dissection specimens yielded 3092 lymph nodes of which 67 (2.2%) were tumor-positive. Twenty-six of these 67 lymph node metastases were micrometastases. Of the 36 tumor-positive neck dissection specimens, 21 contained micrometastases. In 9 tumor-positive specimens only micrometastases were found. This high incidence of micrometastases has important implications for the diagnostic work-up, the treatment, and histopathological examination of the NO neck.