Although dysphagia is a common complication after radiotherapy (RT) for head and neck cancer, its pathogenesis is not completely understood because the swallowing function is affected by complex factors. Appropriate swallowing pressure is an important factor in normal swallowing. When the radiation field includes the pharyngeal segment, intrabolus pressure may be affected. The purpose of this study is to examine the long-term influence of RT on swallowing pressure. Ten patients undergoing treatment for early-stage laryngeal squamous cell carcinoma were included in this study. Sufficient nutritional intake was maintained through oral feeding alone throughout the study period in all of the patients. A high-resolution manometry system with 36 circumferential sensors spaced 1 cm apart was positioned through the nose to record the maximum pressures at the mesopharynx, hypopharynx and the upper esophageal sphincter. The pressures were recorded before and at 6 and 12 months after treatment. There was no statistically significant chronological change in pressures either at meso-, hypopharynx or the upper esophageal sphincter. Even though radiation field includes a part of pharyngeal segment, intrabolus pressure was not found to be affected by the treatment. Despite the disadvantages of RT, the current study did not demonstrate RT had a quantitative influence on swallowing pressure. Further studies are required to clarify the relationship between pharyngeal pressure and the dysphagia induced by RT.