Although local governments attempt to promote sports among all layers of society, people with a lower socio-economic status are still under-represented in grassroots sports. Previous studies indicate that inter-sectoral networks and joint efforts can contribute to an increase in sport participation among these groups, but a systematic analysis of the structure, coordination and interactions in the networks is still missing. Insight into networks to promote sport for disadvantaged people may help in designing effective networks. Therefore, we conducted a social network analysis to explore the network structure and characteristics of networks that promote sport participation among disadvantaged people in three Flemish cities. Our results show that the networks needed to be coordinated by a sport administrator, in the initial stage. Once the network is up and running, coordination can be shared so that the sport administration can rely on the experiences of other sectors. More sport initiatives and a better network structure were found in the cities with a community sport development program, through which the sport-for-all policy is implemented and coordinated, compared to a city without such a program.