In patients with squamous cell carcinoma of the oral cavity and oropharynx, the presence of latero-cervical lymph node metastases was found to be the most important of the better known prognostic factors. Still, today, the most reliable technique by which to detect the presence of lymph node metastases is surgery aimed at the dissection of the latero-cervical space; albeit, this surgical procedure has been shown to be an over-treatment in a large percentage of patients presenting squamous cell carcinoma, clinically, radiologically and histologically negative, at neck level. The technique of intra-operative biopsy of sentinel lymph node, routinely used in the staging and treatment of tumours with elective lymphatic involvement such as carcinoma of the breast and malignant cutaneous melanoma, has progressively caught the attention of head and neck surgeons in the most important referral centres in the world, and, indeed, its role has been hypothesised in the treatment of patients with squamous cell carcinoma of the oral cavity and oropharynx with clinically N0 neck. Preliminary results are reported, concerning the use of this intraoperative sentinel lymph node biopsy technique with double tracer in patients presenting squamous cell carcinoma originating in the mucosa of the upper air-digestive tract, clinically and radiologically free from disease at latero-cervical level.