PURPOSE: To investigate whether the involvement of both registered dietitians and dental hygienists results in greater improvement in swallowing function and activities of daily living (ADL) in patients with dysphagia undergoing rehabilitation. METHODS: Of 467 patients enrolled in the Japanese Sarcopenic Dysphagia database, 433 met the study eligibility criteria in a retrospective cohort study. Patients were divided into two groups based on whether or not they received intervention by both registered dietitians and dental hygienists. Outcomes were changes in the Food Intake Level Scale (FILS) and the Barthel Index (BI) at initial and follow-up assessments. Multiple regression analyses adjusted for age, sex, sarcopenia, dwelling, Charlson comorbidity index, malnutrition diagnosed by the Global Leadership Initiative on Malnutrition, and initial FILS or BI were conducted to examine the relationship between the involvement of both registered dietitians and dental hygienists. RESULTS: The mean age was 80.5 and ± 10.7 years, and 222 were female. Both registered dietitians and dental hygienists were involved in 242 (57%) patients. Median and interquartile range changes in FILS and BI were 1 (0, 2) and 15 (0, 32.5), respectively. In multiple regression analyses, the change in the FILS was significantly higher in the involvement of both registered dietitians and dental hygienists (standardized coefficient = 0.075, P = 0.033), however, the change in the BI was not significantly different between the groups. CONCLUSION: The involvement of both registered dietitians and dental hygienists improved swallowing function, but not ADL. Triad of rehabilitation, nutrition, and oral management may be useful for patients with dysphagia.