On January 12, 2010, a 7.0 magnitude earthquake struck Haiti, which borders the Dominican Republic on the island of Hispaniola. The earthquake's epicenter was 10 miles west of the Haiti capital city of Port-au-Prince (estimated population: 2 million). According to the Haitian government, approximately 200,000 persons were killed, and 500,000 were left homeless. Malaria caused by Plasmodium falciparum infection is endemic in Haiti, and the principal mosquito vector is Anopheles albimanus, which frequently bites outdoors. Thus, displaced persons living outdoors or in temporary shelters and thousands of emergency responders in Haiti are at substantial risk for malaria. During January 12-February 25, CDC received reports of 11 laboratory-confirmed cases of P. falciparum malaria acquired in Haiti. Patients included seven U.S. residents who were emergency responders, three Haitian residents, and one U.S. traveler. This report summarizes the 11 cases and provides chemoprophylactic and additional preventive recommendations to minimize the risk for acquiring malaria for persons traveling to Haiti.