Аннотация:Research with primary care health workers doesn't take in consideration well-being as a strategy for health prevention and health promotion in the workplace. This study aimed to evaluate how social well-being mediates the relationship between the occurrence of aggressive behaviors and psychosocial risks at work in the development of Burnout Syn-drome in 248 primary healthcare workers of Porto Alegre, Brazil. The instruments used for data collection were: sociodemographic questionnaire, the Brazilian Criterion of Economic Classification, a questionnaire about work perception in primary healthcare, the Psycho-social Risks at Work scales, the Healthcare-worker's Aggressive Behavior Scale-Users, the "Spanish Burnout Inventory", and the Social Well-Being Scale. Results show that Social Well-Being is a protective significant mediator between the occurrence of healthcare us-er's aggressive-behaviors and psychosocial work risks in Burnout development. Further psychosocial interventions based on these findings are needed to promote health in this population.