The purpose of this study was to describe the health care access provided to a low-income urban population by a system of county run public clinics. We conducted a cross-sectional interview survey of a random sample of subjects applying for or renewing eligibility to use the public system. The setting was a public system consisting of inner-city community health centers and hospital-based clinics delivering primary care. We interviewed 547 adult nonpregnant subjects; mean age was 41 years; 55% were women, 54% were Hispanic and 28% were non-Hispanic Blacks; 78% had household income below $15,000 per year, and 75% had no health insurance. Access to health care was measured in three ways: physician contact during year prior to survey; and answers to two separate questions concerning delaying needed medical care because it cost too much, and delaying care because it would take too long to be seen. Although 80% of subjects had seen a physician at least once, 46% had stayed away sometime during the year due to financial reasons and 24% had stayed away because of waiting time. Surprisingly, 35% reported private sector use. These rates varied significantly with insurance status. Hispanics had significantly less access by all three measures, even after multivariable adjustment for potential confounders such as sex, age, chronic disease and insurance status. We conclude that this study demonstrates financial barriers to access, while showing substantial private sector contact, even by low-income subjects already using the public sector.