Résumé : Mali has long been a leader in francophone Africa in developing systems aimed at improving aid effectiveness, especially in the health sector. But following the invasion of the Northern regions of the country by terrorist groups and a coup in March 2012, donors suspended official development assistance, except for support to NGOs and humanitarian assistance. They resumed aid after transfer of power to a civil government, but this was not done in a harmonized framework. This article describes and analyses how donors in the health sector reacted to the political unrest in Mali. It shows that despite its long sector-wide approach experience and international agreements to respect aid effectiveness principles, donors have not been able to intervene in view of safeguarding the investments of co-operation in the past decade, and of protecting the health system's functioning. They reacted to the political unrest on a bilateral basis, stopped working with their ministerial partners, interrupted support to the health system which was still expected to serve populations' needs and took months before organizing alternative and only partial solutions to resume aid to the health sector. The Malian example leads to a worrying conclusion: while protecting the health system's achievements and functioning for the population should be a priority, and while harmonizing donors' interventions seems the most appropriate way for that purpose, donors' management practices do not allow for reacting adequately in times of unrest. The article concludes by a number of recommendations.