We have found that performing a Meltzer-Lyon test simultaneously with upper gastrointestinal endoscopy is an efficient as well as accurate technique for diagnosing acalculous cholecystitis. For the patient with upper abdominal pain and normal contrast and sonographic studies, endoscopy is often the next logical step in diagnosis. When the results of endoscopy do not reveal a source of upper abdominal pain, one can proceed directly to a Meltzer-Lyon test. Early diagnosis and cost containment are the obvious advantages of this procedure. The reliability of the Meltzer-Lyon test justifies the additional five to ten minutes of endoscopic time in these diagnostically challenging patients.