This snapshot provides an overview of 4Mi data in relation to the detention of migrants and refugees in West Africa. It is based on 3,094 4Mi interviews conducted between June and November 2019, 30% of which were with women. Interviews took place in Mali (Kayes, Mopti, Gao, Timbuktu and Ber), Niger (Niamey, Diffa, Agadez, N’guimi and Tillabéri) and Burkina Faso (Dori, Bobo Dioulasso and Kantchari).