The integration of ensemble rainfall forecasts to explore the probabilistic framework for flood forecasting is a topic of increasing interest within the hydrometeorological community. As part of the TIGGE initiative, a key component of the THORPEX Interactive Grand Global Ensemble program of WMO, meteorological ensemble forecasts from several centres have been archived since October 2006. Hydrologists are encouraged to use this database to carry out researches on hydrological ensemble prediction. Although hydrological studies based on the TIGGE database are still few, their results indicate that TIGGE can be a promising tool for ensemble streamflow and flood forecasting (see Pappenberger et al., 2008 and Yi et al., 2009 & 2010). Even though these studies are enlightening, they may lack generality, since they are based on a limited number of catchments. The present study proposes an evaluation of hydrological forecasts based on the TIGGE database over a larger set of catchments, under varied climate conditions, to better assess robustness and generality of forecast performance. The study is carried out over 74 catchments in France, with areas ranging from 1000 km² to 44,000 km². Hydrological forecast evaluation is performed at catchment-based spatial scales and for lead-times up to 15 days. Streamflow forecasts are issued by the GRP rainfall-runoff model, driven by ensemble weather predictions from 8 meteorological centres of the TIGGE database. The performances of the ensemble forecasts are evaluated over a 2-year period, from October 2006 to October 2008. Single ensemble prediction systems from each centre, with a number of members ranging from 15 to 51, according to the meteorological centre, are considered in the hydrological model, as well as a combined multi-model ensemble that takes into account all members available at each day of the forecast period.