Aim: To evaluate the impact of xerostomia, edentulism, use of dental prosthesis, and presence of chronic diseases on quality of life in relation to oral health in institutionalized elderly individuals. Methods: This is a cross-sectional study. A questionnaire was administered containing the following instruments: Oral Health Impact Profile (OHIP-14), which measures the quality of life related to oral health; the Summated Xerostomia Inventory questionnaire (SXI-PL) for evaluation of xerostomia, sociodemographic data, clinical description, and patient-reported factors was assessed (edentulism, use of dental prostheses, and chronic diseases). Results: Most elderly individuals did not have any teeth in their mouths and used dental prosthesis. The impact on quality of life, considering the mean of the OHIP-14 scores, was positive in 58.3% of the elderly. Those who used a dental prosthesis were three times more likely to have their oral health negatively impacted (OR=3.09; 95%CI =1.17 8.11), compared to those who did not use, and individuals with xerostomia were more likely to have their oral health negatively impacted (OR=1.57; 95%CI=1.25-1.98) compared to those without xerostomia. There was no difference in the quality of life of individuals with and without chronic diseases. Conclusions: The feeling of dry mouth and use of dental prostheses negatively impacted the quality of life in relation to oral health of the elderly.