The aim of this study was to evaluate the role of supraomohyoid neck dissection (SOHND) in oral carcinoma patients with clinically negative neck nodes. From July 1993 to June 1998, 140 patients with oral carcinomas and clinically negative lymph nodes in the neck underwent elective SOHND in Chang Gung Memorial Hospital, Taiwan. Thirty-seven patients had postoperative radiotherapy.Thirty-four (24.3%) patients had occult cervical metastases. The overall regional control rates were 93.4% vs. 85.3% for pathologically negative vs positive nodes, respectively, with or without adjuvant radiotherapy. Adjuvant radiotherapy significantly improved ipsilateral regional control (P=0.012) in patients with occult cervical metastases but not in patients with negative neck disease. (P=1.0) SOHND is both a diagnostic and therapeutic procedure in patients with negative neck disease. Its therapeutic role in patients with positive neck disease remains controversial. Postoperative radiotherapy significantly improve ipsilateral neck control in patients with occult cervical metastasis.