Childhood anemia is a public health problem in Peru. A variety of preventive strategies are being developed, among them the use of social networks. Little evidence is available about the best ways to interact with audiences in this space. The purpose of the study was to explore the perception of users of social networks of the Peruvian Ministry of Health about a video promoting food to reduce the risk of childhood anemia and estimate the scope and interaction it achieved through the social networks. An exploratory qualitative-quantitative study was conducted of an intervention based on a music video disseminated by the Ministry of Health in the social networks Facebook, Twitter and YouTube. Most of the users commenting on the video (58 / 77) in Facebook reported a positive perception. The largest number of replays was reached at four months' follow-up in Facebook (364 000 replays), trebling the results of Twitter and YouTube together. The broadest scope was achieved during the first week. The highest interaction rate at four months occurred in Facebook (7.1%), followed by Twitter (5.2%) and YouTube (0.3%). The greatest scope and interaction rate of the study video occurred in Facebook. Perception was positive, but the interaction rate was low. Social networks are a swift though ephemeral form of communication with a great potential in public health.