Repetitive, spontaneous contractions of the proximal esophagus have recently been identified as a feature of achalasia. This article documents similar findings in six patients with Parkinson's disease. Parkinson's disease and achalasia share many common features neurologically. Both have Lewy bodies in the esophageal myenteric plexuses and the substantia nigra, in addition to evidence of degeneration of the dorsal motor nucleus of the vagus. The esophageal features radiologically and manometrically are also similar. Repetitive proximal esophageal contractions may represent another link between these diseases. They have also been reported in scleroderma. We speculate that the common link between all three disease processes may be poor distensibility of the esophagus.