Dysphagia induces silent aspiration, which is a known risk factor for aspiration pneumonia in the elderly. Dysphagia is associated with impaired substance P secretion. Because nicergoline was recently reported to enhance substance P secretion, it may improve dysphagia by upregulating substance P; however, roles for nicergoline in this process have not been demonstrated. We therefore compared the effects of nicergoline on serum substance P and dysphagia with the effects of imidapril, an angiotensin-converting enzyme (ACE) inhibitor whose efficacy in improving dysphagia and preventing pneumonia has been previously demonstrated.We randomly assigned 60 elderly patients with both dysphagia and a previous history of pneumonia to receive either imidapril (5 mg/d; n = 30) or nicergoline (15 mg/d; n = 30) for 6 months. Primary outcomes were the effects of these drugs on the substance P level and dysphagia 4 weeks after the start of treatment. Secondary outcome was the effect of these drugs on pneumonia recurrence during the 6 months of treatment.Significant elevations of serum substance P were obtained by both medications after 4 weeks of treatment. Patients whose dysphagia was improved showed significantly increased serum levels of substance P. There was no statistically significant difference in the overall proportion of patients who showed improvements in dysphagia and pneumonia recurrence with imidapril or nicergoline treatment. Nicergoline, but not imidapril, seemed to be more effective at improving dysphagia and elevating serum substance P in patients with dementia.In conclusion, nicergoline has a comparable effect to ACE inhibitors for improving dysphagia. Nicergoline might be a novel regimen for the treatment of dysphagia in the elderly who are not treatable with ACE inhibitors.