We carried out a prospective, double-blind study at three institutions, comparing esophagography with esophagoscopy for the detection of simultaneous cancer of the esophagus in patients with other squamous cell cancers of the head and neck. The goal was to determine whether esophagography and esophagoscopy are necessary for the examination of patients before treatment. One hundred eighty-two patients were studied; both examinations were done in 148 patients. Twenty-one patients could not undergo esophagoscopy; esophagography was inadequate in 9 patients; 4 patients could have neither examination. Concordance was noted between the two procedures in 86.5% of patients. Sixty-five percent were normal, and 21.5% were abnormal. One esophageal cancer was found in this series that was diagnosed by both methods. Our data suggest that esophagoscopy and esophagography may be complementary in evaluating squamous cell carcinoma of the head and neck in patients before treatment. Esophagography alone was useful in patients in whom esophagoscopy could not be performed.