This paper evaluates the knowledge of community health workers in complementary feeding and their association with sociodemographic characteristics, work routines and describes the resources available in primary care facilities to master this topic. We applied questionnaires to the responsible for health services and to community health workers, the latter consisting of a knowledge test that allowed the calculation of scores according to the number of correct answers in multiple-choice questions. There was a positive association with age, length of service, home visits to children under 24 months, providing guidance or seeking information about complementary feeding with the knowledge in feeding in the first 24 months of life. There were discrepant responses by health services and the community health workers regarding training, government materials and child growth monitoring. Greater mastery was noted in breastfeeding in relation to complementary feeding. Therefore, primary care facilities should provide support and resources to increase knowledge in complementary feeding through training and access to government materials.