This paper aims at exploiting grain price data to detect the warning signs of looming food crises in Mali, Burkina Faso and Niger. Firstly we identify markets which play a leading role at the national and regional level. The second step consists of identifying price crisis periods and characterizing price movements during the period preceding a crisis. This analysis leads to the identification of early warning indicators whose relevance is tested using panel data qualitative choice models. The results show that monitoring price movements at leading markets during crucial periods of the year can help in forecasting future price crises.