This is the review of a multicentre study to set practical guidelines for sentinel node techniques (SLN) in upper aerodigestive tract (UADT) squamous cell carcinomas including classical and extended indications. SLN biopsies are strictly indicated in patients with clinically and radiologically N0 necks as well as previously treated necks or even previously operated primaries. The nanocolloid tracer is injected either pre- or intraoperatively. The tracer is injected circumferentially in the healthy submucosa surrounding the tumour. The decay rate is 25%/six hours and a dynamic acquisition over 20-30 minutes is thus justified to detect the first echelon nodes. If no activity can be detected delayed scans can be performed up to two hours later. In the OR hot spots are detected by a gamma camera and a short incision, along the lines of a possible neck dissection, is performed. The excised material is tested for radioactivity and a minimum signal to noise ratio of 10 is acceptable. Frozen section biopsies are not systemically performed on positive nodes. In 10-15% of cases the frozen sections are positive and a neck dissection is then performed in the first stage. Usually the neck dissection is delayed for a second stage when the definitive biopsies are reviewed. This technique provides an individualised approach to the management of patients with clinically negative necks in T1 and T2 oral and oropharyngeal carcinomas.