Responding to the medical needs of the homeless population across the United States exact large costs on the health care system. To provide effectively for such vulnerable populations, health care systems require creative and efficient strategies of service organization tailored to the specific needs of the homeless. However, such needs often vary by geographic region due to the inherent diversity of the population. Currently, no published medical evaluation of the urban homeless in Texas exists. Therefore, this study examines 93,074 diagnoses given to 20,331 homeless patients seen in a seven-year period in a primary care mobile and fixed clinic system. The most frequent disease conditions evaluated in this cohort of patients are reported. These findings may be useful to clinical site managers and health care planners contemplating an outreach program for the homeless.