INTRODUCTION: The government plan for the fight against drugs and addictive behaviors 2013-2017 includes several actions concerning French overseas territories, in particular to strengthen information on drug addiction. The Interministerial mission for combating drugs and addictive behaviors (MILD&CA) has commissioned the Bordeaux addictovigilance center to strengthen exchanges on addictovigilance with Reunion Island and Mayotte and to make an inventory of problematic drug use in these two French departments of Indian Ocean. METHOD: Two pharmacologists went on an assignment 4.5 days in Reunion and 2 days in Mayotte and met more than fifty people involved in addictology. RESULTS: In Reunion Island, alcohol is the psychoactive substance by far the most used, followed by zamal, the local name for cannabis. There is a strong tradition of medicines diversion, including trihexyphenidyl, barbiturates and more recently, benzodiazepines. Heroin and cocaine are rarely available. Poly drug use is common. In Mayotte, bangue, the local name for cannabis, is the most used psychoactive substance. The use of "chimique" has emerged in 2012-2013. It is used mainly by teenagers and young adults, causing numerous cases of hospitalizations and consultations in addictology in 2015. These could be synthetic cannabinoids bought on the Internet. DISCUSSION: It is important to report new or serious cases to better take into account the particularities of these two departments in the French addictovigilance data and to enable analysis of substances consumed.< Réduire