Homelessness is a growing problem in Canada. Homeless people suffer from high rates of illness. Despite their higher need for health care, little is known about their health care use, the barriers to obtaining care, or the effectiveness of specific models of primary care for homeless people. About 32-54% of homeless people report that they have received care in an emergency department in the last year, which is more than three times the rate of use in the general population. It is plausible that if homeless patients were provided with better access to primary care services, they would be less likely to seek care in emergency departments, however, this hypothesis remains unproven. This question has important implications for the organization and philosophy of health care delivery for the homeless.