Objectives: To examine the relationship between edentulism and the progress of multimorbidity, and the role of nutritional intake and behaviours among older Americans. Methods: We used 7 waves (2006-2018) of the Health and Retirement Study, a longitudinal survey of older Americans (number included in analysis 2,224). Edentulism was assessed in 2006 and 2012. Multimorbidity was indicated by 5 self-reported conditions: diabetes, heart conditions, lung diseases, cancer, and stroke. Behavioural factors were smoking, excessive alcohol consumption, physical activity, and body mass index. Nutritional intake was calculated by summing 10 nutrients (Protein, Vitamins C, D, B12, E, Calcium, Zinc, Polyunsaturated fatty acids, Folate and ß- carotene). Multilevel models for analysis of longitudinal data were used to assess the association between change in repeated measures of multimorbidity (between 2006 and 2018) and edentulism (2006) adjusting for nutritional intake, behavioural and socioeconomic factors. Results: Participants who were edentate in 2006 and 2012 had higher rate-ratios (RR) for change in multimorbidity between 2006 to 2018 (RR: 1.29 and 1.28, respectively). After adjusting for socioeconomic factors, total nutrients and behavioural factors, these RR attenuated to 1.12 (95%CI: 1.06, 1.18) and 1.10 (95%CI: 1.05, 1.16), respectively. Total nutrition was negatively associated with progress of multimorbidity, but after adjusting for socioeconomic and behavioural factors the association became insignificant. Total nutrients rates in 2013 were significantly lower among those who were edentate in 2006 and 2012. Conclusion: There was a longitudinal association between edentulism and progress of multimorbidity. The relationship appeared to be mediated be behaviours and nutrition. Keywords: multimorbidity, Aging, Edentulism, Longitudinal Studies, Nutrient Intake