The technique of esophageal scintigraphy was developed as a sensitive, quantitative, noninvasive test of esophageal transit. Esophageal scintigraphy was performed in 40 asymptomatic normal volunteers in order to determine the effect on esophageal transit of the following: body posture (sitting vs. supine), liquid vs. solid, the solid being either a standard #4 gelatin capsule of the size used for antibiotic capsules, or a cube of solid food such as cooked chicken liver. The results showed that liquids emptied completely from the esophagus after one swallow, whether supine or sitting. Capsules or liver cubes, when ingested without water, frequently remained in the esophagus for up to two hours without the subject's having any sensation that the solid had not left the esophagus. Both capsules and liver cubes cleared the esophagus better in the upright than in the supine position. When gelatin capsules were swallowed with as little as 15 ml of water, but after a preliminary sip of water, there was complete transit in each case. The study suggests that the practice of assisting patients into a sitting position and instructing them to take a sip of water before attempting to swallow a capsule will assure better transit of the capsule even when swallowed with as little as 15 ml of water. This may reduce the incidence of esophagitis following oral antibiotics, and of esophageal erosions from aspirin-containing medications.