To estimate human resources (HR) needed to deliver prevention and health promotion actions to the population of 20 years and more in units of primary health care (UPHC). Materials and methods. We included 20 UPHC; one urban and one rural for each of the ten selected Mexican states. HR were estimated based on the time to do prevention and health promotion activities, from which a budget was calculated. Measures of central tendency and dispersion were reported, using the ANOVA test and the Wilcoxon test. Results. The number of health professionals estimated in UPHC with spent time is less than the number estimated with required time. Conclusions. The estimated density of health professionals per population needed to offer prevention and health promotion activities for people 20 years and more in UPHC is greater than the current density of health professionals.