Coalitions play a critical role in how health care organizations address complex health problems. The current report aims to support people who work in community health coalitions by providing insight about the nature and development of these coalitions. Information for the report came from a multiyear assessment and formal evaluation of coalitions focused on tobacco control. Research methodology included semi-structured interviews, observations, and closed-ended surveys. The report stressed the importance of recognizing how aspects of the environment such as culture, ethnicity, and geography influence coalitions. Coalitions are also defined by the diversity of their members. Along that vein, strategies to recruit and retain members are important in coalition development. The organizational structure of coalitions along with resources, such as staffing and funding, influence how coalitions are run. Leadership is integral to coalitions; members can exert leadership in formal or informal ways with leadership style and rules for succession being key for successful coalitions. The manner in which decisions are made can help make coalitions more productive and lead to constructive conflict resolution. The stages of coalition development include identifying members and the common ground that exists between them; implementing activities and projects; and either ending or starting new coalitions when conflict cannot be resolved. Coalitions' movement through these stages may involve stasis, forward or backward movement, or a combination of each. Trust, adaptation, and dedicated staff are among the factors that can help sustain community health coalitions over long periods of time.