The evaluation of suspected esophageal chest pain is frustrating because of difficulty in clearly implicating the esophagus. Balloon distention was considered as a new provocative test in the esophagus because it has been shown to safely produce pain in other hollow gastrointestinal organs. Studies were performed in 50 chest pain patients (mean age 50 years) with negative coronary arteriograms and 30 healthy volunteers (mean age 41 years). A polyvinyl balloon (length 30 mm; maximum diameter after 10 cc distention 25 mm) was positioned 10 cm above the lower esophageal sphincter and inflated with 1-cc increments of air to a total volume of 10 cc. Using a placebo-controlled design, pain response was recorded along with associated balloon volumes. Pain occurred in 28/50 (56%) patients and 6/30 (20%) volunteers (P less than 0.005). Symptoms were unassociated with ECG changes, and resolved immediately with decompression of the balloon. Most patients (24/28) experienced their typical chest pain at less than or equal to 8 cc distention, while all volunteers with pain noted it at greater than or equal to 9 cc distention. For this reason, 8 cc was considered a diagnostic cutoff. Chest pain patients were also studied with two other commonly used provocative tests: intraesophageal acid perfusion and intravenous edrophonium (80 micrograms/kg). These tests reproduced pain in only 12 (24%) patients. Positive balloon studies occurred in 11 of these patients and identified an additional 13 patients, thus increasing the diagnostic yield from 24% to 48%. Only one of 22 (4%) balloon-negative patients had a positive acid-perfusion or edrophonium test.