Inappropriate complementary feeding is one of the major causes of malnutrition in young children in developing countries. We developed an educational intervention, delivered by local health-care providers, aimed at improving complementary feeding practices and child nutrition. Eight townships in Laishui, a rural area in China, were randomly assigned to the educational intervention or control group. A total of 599 healthy infants were enrolled at age 2-4 months and followed up until 1 year of age. In the intervention group, educational messages and enhanced home-prepared recipes were disseminated to caregivers through group trainings and home visits. Questionnaire surveys and anthropometric measurements were taken at baseline and ages 6, 9 and 12 months. Analysis was by intention to treat. It was found that food diversity, meal frequency and hygiene practices were improved in the intervention group. Infants in the intervention group gained 0.22 kg more weight (95 % CI 0.003, 0.45 kg, P = 0.047) and gained 0.66 cm more length (95 % CI 0.03, 1.29 cm, P = 0.04) than did controls over the study period. Findings from the study suggest that an educational intervention delivered through local health-care providers can lead to substantial behavioural changes of caregivers and improve infant growth.