We studied barriers to HIV care among HIV-positive Latinos in the US-Mexico border region, where HIV prevalence is increasing. HIV-positive participants receiving HIV care were recruited from clinics in Southern California and underwent structured interviews (n = 157). Logistic regression explored covariates associated with > or =1 barrier to HIV care. HIV-positive patients were mostly male (84.7%), of Mexican-origin (82.8%), and had a mean age of 37.3 years. Among males (n = 133), 67% identified as men who have sex with men. In the prior year, patients received the following care in Mexico: HIV care (33.1%), non-HIV care (43.3%), prescription medications (51.6%), and traditional medications/herbs (17.2%). The most common barriers to HIV care included stigma and medication side effects concerns. Factors independently associated with > or =1 barrier to HIV care were HIV diagnosis >1 year ago; being of Mexican-origin; crossing the US-Mexico border <5 times in the past year; obtaining medications in Mexico; and age. Findings illustrate that bi-national health care utilization is common, which has implications for HIV service delivery in both countries. Additional studies are needed to better understand individual, provider and system level barriers to HIV care in the San Diego/Tijuana border region.