Abstract Objective This study explores the relationship between nutritional status and oral health quality of life, the self-efficacy of older inpatients and the correlative factors. Methods In this study, the convenience sampling method was used to select 307 older inpatients in the southern section of the Renji Hospital affiliated to Shanghai Jiao Tong University School of Medicine from October to December 2020 as the main research participants. A mini nutritional assessment questionnaire was used to assess nutritional status, and the Chinese version of a geriatric oral health assessment index questionnaire was used to determine the oral health quality of life. Self-efficacy was assessed by a general self-efficacy scale questionnaire. Descriptive statistics were used to analyse data using the SPSS 22.0 software. Pearson correlation and multiple linear regression analysis were applied to explore the correlation between variables and factors concerned with nutritional status, respectively. Results The results of this study showed that the self-efficacy and oral health quality of life of older inpatients were at a moderate level. Among the patients, 263 had one or more tooth defects, and only 128 had oral restorations or wore dentures. The risk of malnutrition in hospitalised older patients was 37.1%, and the incidence of malnutrition was 13.4%. The risk factors of nutritional status of older patients were age, oral-related quality of life, prealbumin index, self-efficacy, chronic disease, monthly income and tooth defect (P