Head and neck cancer is often associated with second primary neoplasms. These cancers most commonly involve other regions of the head and neck, esophagus, and lung. The majority of cases are also squamous cell carcinomas. In view of this rather frequent occurrence of multiple primary cancers and how they adversely affect the patient's survival, it becomes imperative to analyze how the clinician can intervene effectively. One such approach is to detect multiple primaries as early as possible. As such, panendoscopy as a part of the tumor-staging procedure has been advocated by many investigators to search for simultaneous second primary malignant neoplasms in patients presenting with head and neck cancer. In a 24-month period, data were gathered from 127 consecutive patients referred to University Hospital, Ghent with previously untreated, squamous cell carcinomas of the head and neck. One hundred-eighteen patients underwent an endoscopic examination under general anesthesia, during which 4 simultaneous second primary tumors were found in 3 patients. This represents an incidence of 3.4% of simultaneous second primary neoplasms. The resuits for the different parts of the endoscopy are discussed and compared with literature findings. Guidelines are given for the initial evaluation of the head and neck cancer patient.