Implemented in 2000, CeaseFire is the first initiative of the Chicago Project for Violence Prevention, an umbrella organization at the School of Public Health at the University of Illinois at Chicago. CeaseFire works with community-based organizations to develop and implement strategies to reduce and prevent violence, particularly shootings and killings.

CeaseFire relies on outreach workers, faith leaders, and other community leaders to intervene in conflicts, or potential conflicts, and promote alternatives to violence. CeaseFire also involves cooperation with police and it depends heavily on a strong public education campaign to instill in people the message that shootings and violence are not acceptable. Finally, it calls for the strengthening of communities so they have the capacity to exercise informal social control and respond to issues that affect them.

CeaseFire is composed of five core components: community mobilization, youth outreach, public education, faith-based leader involvement, and criminal justice participation.

The goal of CeaseFire is to interrupt the cycle of violence by changing norms and promoting positive behavior change.

After a year of needs assessment, planning, and building collaborative relationships at the local level, CeaseFire was formally launched in early 2000 with outreach workers in the West Garfield Park neighborhood of Chicago. Police Beat 1115 was chosen as the first CeaseFire zone in large part because of the high number of shootings. In the first year of CeaseFire, shootings in beat 1115 dropped by 67%.

By the beginning of 2006, CeaseFire was either established or in the process of being implemented in 15 neighborhoods in the city and at sites in five other cities in Illinois.

According to external evaluations conducted by the Chicago Police Department and university researchers, CeaseFire prevented an estimated 337 shootings in intervention neighborhoods between 2000 and 2003, and resulted in reduced overall shootings and killings, safer neighborhoods, and improved community health, as well as cost savings from Medicaid and community justice costs.