Dengue is a mosquito-transmitted acute disease caused by any of four virus serotypes (DEN-1, DEN-2, DEN-3 and DEN-4) and is characterized by acute manifestations that can include fever, headache, myalgia, arthralgia, rash, nausea, and vomiting. On August 25, 1995, public health authorities in Mexico notified the Texas Department of Health (TDH) of an ongoing outbreak of dengue fever in the state of Tamaulipas, which borders south Texas. Because of the year-round presence of the Aedes aegypti mosquito (a major vector for dengue) in southernmost Texas and the frequent movement of persons across the U.S.-Mexico border, the outbreak in adjacent Tamaulipas suggested an increased potential for imported and autochthonous cases in Texas, as had occurred during 1980 and 1986. In response to the notification from Mexico, TDH intensified surveillance efforts for dengue, resulting in identification of 29 laboratory-diagnosed cases in Texas residents, including seven persons with no history of travel outside the state. This report summarizes results of dengue surveillance in the U.S.-Mexico border area during 1995-1996.