Community collaborations have become increasingly common responses to prevent the occurrence of complex public health problems, such as violence, substance abuse, HIV/AIDS, and others. A key unanswered question is: what predicts sustainability of collaboratives? This article explores this question through a cross-site evaluation of 12 local collaboratives funded through the National Funding Collaborative on Violence Prevention (NFCVP). Conducted as longitudinal case studies, the evaluation is distinct from previous efforts in incorporating data from multiple sources. The results confirm findings from previous studies that have identified having a history of collaboration, a diverse and broad coalition, a clear vision and operation guidelines, and diversified and sufficient funding as key sustainability factors. In addition, this study has found that collaborations that are growing and expanding are more likely to have high resident involvement, a mix of professional and grassroots representation, and a facilitating, rather than direct, role in conducting prevention activities.