It is evident that carcinomas of the upper aerodigestive tract are increasing. Unfortunately advanced tumor stages prevail when patients enter clinical treatment. The causes for delayed tumor diagnosis are manifold, they can be "organ-, tumor-, patient- and doctor-related". Only by means of a complete and thorough examination, employing both an endoscope and a microscope, as well as by consequent histological classification of visible proliferations of uncertain dignity, an adequate diagnosis and treatment of pre- and early cancer stages can be accomplished. The organ-specific characteristics and organ-independent common features are described with respect to early cancer diagnosis. By presenting the diagnostic and therapeutic procedures applied to early cancer stages, the relative merits of smear cytology and histology (cup forceps vs excision biopsy) are discussed. Ultimately, the detection of clinically occult primary tumors is dealt with by referring to a number of principal signs such as nodes in the neck, secondary otalgia, etc. The possibilities of early detection of neck metastases are pointed out and the importance of panendoscopy for early diagnosis of simultaneous secondary tumors is emphasized. In conclusion, the consequences for improved early cancer diagnosis are presented in detail.