There are two competing research explanations to account for Latinos' underutilization of health services relative to non-Latino Whites in the United States. One hypothesis examines the impact of health locus of control (HLOC) beliefs, while the other focuses on the role of access factors on health care use. To date, the relative strength of HLOC beliefs in explaining Latinos' use of health care services in the context of access factors is inconclusive. This study, therefore, tests and compares both explanations. We analyzed data from the 2007 Pew Hispanic Healthcare Survey, a nationally representative survey of 4,013 Latino adults. HLOC beliefs had a statistically significant but weak impact on health care use after accounting for access factors. Having continuous health insurance coverage and a usual place of care to go when sick or in need of health advice were much more influential in predicting health care use than HLOC beliefs. This study suggests that disparities in health care service use among Latinos are much more an issue of access than it is an issue of HLOC beliefs. Implications for public health research and intervention efforts that aim to reduce health disparities in health care use are discussed.