School meals can have a key function in promoting children’s health. However, simply providing a free school meal is not a guarantee that pupils will actually eat the food. The purpose of this study was to explore factors influencing pupils’ participation in free school meal schemes in Oslo The study has a qualitative research design, inspired by grounded theory. Data were collected through interviews with pupils, teachers and parents, and participant observations in two schools participating in a pilot project funded by Oslo Municipality. Line-by-line coding, memo writing and a constant comparative technique were used to analyse the data. One primary school and one lower-secondary school in different districts in Oslo that were implementing two different free school meal models. 39 pupils (5th–10th grade), 15 parents and 12 school employees were included. Four main factors related to pupils’ participation to free school meals emerged from the analysis: the popularity of the food served, the attraction to the nearby shopping centre, social aspects and predictability. To promote pupils’ participation in free school meal schemes, schools need to solve the challenges of balancing between healthy food and popular but often unhealthy food. Children and parents involvement, regularity of the meals provision, a good flow of information and the creation of a friendly eating environment are recommended