With experience, air contrast examination of the esophagus, stomach, and duodenum can be performed routinely as quickly and easily as the standard UGI. The air contrast examination is superior for detection of small gastric polyps and the Japanese have found it superior for detection of early carcinoma. The postoperative stomach and the fundus and cardia are most easily examined by air contrast. Clear superiority in the diagnosis of peptic ulcers and peptic esophagitis has not been proved. The most accurate routine examination may be a multiphasic or combined approach utilizing air contrast views as well as filled compression views and careful fluoroscopy. With respect to the colon, we do not suggest that air contrast BE must be done exclusively. However, it is superior for the detection of polyps and small carcinomas. The technique should be available in all radiology departments and should be an integral part of the evaluation of patients at increased risk of developing carcinoma. This includes patients over 40 years of age, with chronic ulcerative colitis, familial multiple polyposis or Gardner's syndrome, family history of inherited cancer, and medical history of adenomatous polyps, colorectal cancer, or female genital cancer. In addition, air contrast enema should be utilized for the sensitive and accurate evaluation of early inflammatory bowel disease. Finally, with respect to the colon examination one fact must be stressed. Irregardless of full column or air contrast method, most missed lesions are due to poor bowel preparation, poor technique, or perceptive error by the radiologist. There can be no substitute for a clean colon, meticulous attention to technical details, and careful review of the radiographs.