Between 1998 and 2006, 1,400 cases of malaria (56.8%) occurring in Côte d'Ivoire and 1,064 (43.2%) following a stay in Côte d'Ivoire were reported among military personnel serving on peacekeeping missions. The annual incidence rate of cases occurring in Côte d'Ivoire decreased between 1998 and 2001, falling from 294.7 to 44.7 per 1,000 person-years. With the launch of Operation Licorne in September 2002, an increase was noted from 2001 to 2002 (134.5). The rate then decreased, stabilizing in 2005 (27.5) and 2006 (28.0). The same trends were observed upon return. Plasmodium falciparum accounted for 78.9% of cases, P. malariae 2%, P. ovale 8%, P. vivax 1.8%, mixed forms 2.7%, and Plasmodium sp. 6.6%. All P. falciparum isolates tested in vitro are sensitive to quinine, lumefantrine, dihydroartemisinin, and atovaquone. Forty percent of the isolates are resistant in vitro to chloroquine, 29% to mefloquine, and 41% show reduced sensitivity to cycloguanil. To improve malaria prevention, it is essential to strengthen health education activities, conduct behavioral surveys, provide physicians with tools to monitor adherence, and evaluate short-term chemoprophylaxis upon return. (R.A.)