Recent outbreaks of chikungunya fever in the Indian Ocean and India have raised concern about the epidemic potential of this previously obscure arbovirus. This infection, caused by chikungunya virus (CHIKV), presents with a triad of high fevers, polyarthralgias and a rash. Postinfection arthralgias and fatigue can last months, and recent crude mortality data from afflicted populations suggest that CHIKV may be more virulent than previously thought. In addition, CHIKV attack rates can be higher than 50% in susceptible populations. Finally, Aedes albopictus, the main mosquito vector in the most dramatic epidemic on Reunion Island, is expanding its range worldwide. Thus, there is some concern among public health and arbovirus experts that CHIKV may follow the same epidemic pattern as West Nile Virus did in 1999 in the US. This article will review what is known about CHIKV and address infection in travelers and the potential for worldwide spread.