ABSTRACT The present study aimed to analyze trends in the prevalence of overweight and obesity in Primary Health Care users in Piauí between 2012 and 2021. We conducted an ecological study with data from the Food and Nutrition Surveillance System. Overweight and obesity were classified as recommended by the World Health Organization. A linear regression was performed to estimate the trend in the prevalence of overweight and obesity. There was an increase in the prevalence of overweight and obesity in Piauí in the period studied in all age groups and in both sexes. However, the growth trend was stationary for overweight in males in the age groups of children and adolescents, and for obesity in both sexes amongst 0-9-year-olds. The study showed an increase in the prevalence of overweight and obesity between 2012 and 2021 in all age groups and in both sexes. However, the growth trend was stationary in some.