Little is known about chikungunya fever and, until March 2005, this abovirosis was seldom part of the differential diagnosis in the case of a patient with fever after travel return; at this time, a major outbreak of this self-limiting febrile illness was taking place in East Africa heading towards India and now also present in South East Asia. Although the evolution of this arbovirosis is usually favourable, important complications can appear in patients with initial comorbidities and in infants or elderly people. A simple serology can be used to show paraclinical evidence. The use of computer databases and internet surveillance networks is a precious help in establishing the differential diagnosis of patients with fever after travel return.