On June 27, 2014, the Florida Department of Health in Miami-Dade County was notified by the Florida Poison Information Center Network of a patient with travel to Southeast Asia who was suspected of having chikungunya virus infection. After further investigation and additional testing, it was determined that the patient had not recently traveled to an endemic area, and this case was confirmed as the first locally acquired chikungunya case in the continental United States. Since the first case of locally acquired chikungunya virus infection in the Americas was reported on the Caribbean island of St. Martin in December 2013, the United States has seen an increase in chikungunya cases among travelers returning from areas where chikungunya has become endemic, particularly the Caribbean and South America. Compared with other states, Florida has seen an especially large number of chikungunya fever cases. During January 1-October 14, 2014, a total of 272 imported cases were reported in Florida, compared with 1,110 reported in the other 47 contiguous states. In addition, 11 locally acquired chikungunya cases have been identified. The recent spread of the virus and the presence of competent mosquito vectors provide the conditions for transmission of chikungunya virus in Florida.