The Aedes albopictus mosquito, or tiger mosquito, a vector of dengue and chikungunya, has been present in mainland France since 2004. It poses a risk of local transmission of these arboviruses due to the regular introduction of the viruses by individuals who become infected while traveling to areas where these viruses circulate. In mainland France, epidemiological surveillance has been in place since 2006. It comprises two permanent national systems based on mandatory reporting (DO) and a network of laboratories, as well as a local, seasonal system of enhanced surveillance in departments where Ae. albopictus is established, during its active period from May 1 to November 30. In 2015, in mainland France, 52 cases of chikungunya and 167 cases of dengue were reported through mandatory reporting; 425 cases of chikungunya and 538 cases of dengue were identified by the laboratory network. From May 1 to November 30, 30 cases of chikungunya and 131 cases of dengue were confirmed in the 22 departments where Ae. albopictus was present. With the exception of the 6 autochthonous cases of dengue in Languedoc-Roussillon-Midi-Pyrénées, all cases were imported. Imported cases of chikungunya or dengue in mainland France partly reflect the epidemiological situation in the travelers’ areas of origin. Despite the absence of an epidemic in the French territories of the Americas (TFA) in 2015, the number of imported cases remains significant. With the spread of Ae. albopictus in mainland France and the emergence of the Zika virus, the risk of local transmission is increasing. It is necessary to regularly inform travelers going to or returning from areas where these viruses circulate, as well as healthcare professionals, so that they can relay prevention guidelines and participate in surveillance.