Twenty-three patients with progressive systemic sclerosis (PSS) were studied by radionuclide esophageal transit (RT) and esophageal manometry. Twenty-two patients had abnormal manometry ranging from lower esophageal sphincter incompetence to aperistaltism. Of these 22 patients, twenty (91%) had abnormal RT with prolongation of transit time. A characteristic RT pattern showing stagnation of the radionuclide in the distal and middle segments of the esophagus was demonstrated in 82% of the patients with advanced sclerodermatous involvement of the esophagus. Fifteen of the 19 controls (79%) studied had a normal RT. Four showed prolongation of transit time without stagnation. We conclude that RT is a safe, noninvasive, highly sensitive method which might be used as an alternative to esophageal manometry. However, it may lack specificity.