We present two cases of P. falciparum malaria in visitors to tourist resorts on the East Coast of the Dominican Republic, traditionally believed to be an area without risk of malaria. In both patients the malaria was severe (with 20% parasitization in one) and there was a long interval between the onset of symptoms and diagnosis. These cases are possibly related (along with a further 17 reports by the Centers for Disease Control and Prevention) to an increase in the population of Anopheles sp as a consequence of increased rainfall and floods provoked by a hurricane in September 2004, as well as to the presence of a semi-immune population (Haitian immigrants working in the construction and tourist sectors). Both physicians and patients should be aware of this outbreak so that adequate precautions can be taken and early diagnoses can be made.