We examined the dynamics of capsule swallowing by healthy young men using the anterior-posterior view of videofluoroscopy as a first step in a study on capsule swallowing by dysphagic patients. The subjects were 14 healthy men who did not have any complaint of dysphagia. They were asked to swallow a #4 hard gelatin capsule filled with barium sulfate with 15 ml of water during the videofluoroscopic examination. This examination was repeated three times for each subject (total of 42 trials). In four of the 14 subjects, a swallowed capsule was retained at the upper esophageal sphincter, or the broncho-aortic constriction of the esophagus, or the lower esophageal sphincter. Except where retention occurred, the average capsule transit time from the mouth to the stomach was 6.0 +/- 2.4 s. Three of the four subjects who had capsule retention did not realize that the swallowed capsule was retained en route to the stomach. By considering the dynamics of swallowing a capsule with 15 ml of water in healthy men, we should be able to reveal the dynamics of capsule swallowing in dysphagic patients, and the capsule transit time from the mouth to the stomach.