There is a dearth of literature describing the treatment needs of substance-abusing or chronically mentally ill homeless individuals who frequently utilize emergency medical services. This homeless subset represents a discrete population in the larger homeless community. We describe a pilot program, supported by local county public funds, and conducted by a local nonprofit social work agency, which was designed to provide intensive case management services to such a population. Outreach and case management activities resulted in linking clients to a broad range of entitlements and community services. Among those receiving outreach and case management services (n = 10), emergency services decreased by 58% in the year following referral compared to the year before (p <.03). Emergency services for the purpose of this study are defined as ambulance response and transport followed by emergency room admission and treatment. Those in a comparable control group (n = 8) showed no decrease in emergency service use. These results suggest that such community-based outreach programs can significantly improve patient outcome and provide substantial cost savings for local governments and hospitals.