Abstract This study aims at describing the evolution of Spanish population preventive practices during the COVID-19 pandemic of the between January and June 2021, and differences by age group. Data was drawn from the COSMO-Spain online survey, rounds (R) 4, 5 and 6. Multiple linear regression models with preventive practices as dependent variable were performed. Preventive practices (p = 0.001) and concern about coronavirus (p = 0.003) decreased throughout the three rounds, knowledge decreased from R4 to R6 (p = 0.002) and health literacy had a higher value in R6 (p