ABSTRACT Objective Evaluate the factors associated with diet quality of older adults from the city of São Caetano do Sul, São Paulo, Brazil. Methods A cross-sectional study was carried out on a sample of 295 older adults receiving care in health care units in São Caetano do Sul. Diet quality was assessed using the Brazilian Healthy Eating Index. The associations between the diet quality mean score and the socio-demographic, economic, and anthropometric characteristics and lifestyle and health conditions were verified using multiple linear regression. Results Lower diet quality mean score were associated with the variables: marital status (widowed or separated) (β=-2.02; p=0.047), retired (β=-4.24; p=0.034), and smoking (β=-8.06; p=0.001); whereas higher diet quality mean score were associated with higher education level (9 years or more) (β=3.49; p=0.013). Conclusion Individuals with higher education level had better diet quality, and those who were widowed or separated, retired, and smokers had worse diet quality indicating that socio-demographic, economic, and lifestyle are factors that can influence food choice of older adults.