This article aims to explain variations in the participation of civic organizations in neighborhood projects. In particular, we inquire into the impact of the social networks of more than 400 local civic organizations on their participation in neighborhood projects in two Dutch cities. Two strands of literature constitute the basis for our arguments. First, there is much research on the determinants of individual participation showing that tenure, social-economic status, and being a member of the majority matter considerably. Second, network studies demonstrate that the structure and content of one's relationships substantially influences successive actions. Our expectations are based on both bodies of knowledge. We survey the civic organizations in eight neighborhoods and analyze the impact of their social networks using multinomial logistic regression models. The results show that the actual number of relations in the network and the density of the networks are positively associated with participation in neighborhood projects. Furthermore, we show that organizations with high proportions of ethnic minorities provide less support, despite their networks. Finally, organizations with many professionals working for them participate more if their networks are taken into consideration.