With the objective of understanding the potential and limitations of available precipitation products for hydrological studies, this paper compares six daily and sub-daily precipitation datasets and their impacts on the water balance of the Negro River basin in the Amazon basin. The precipitation datasets contain gauge-based data [data derived from the Hybam Observatory Precipitation (HOP) dataset and provided by the Climate Prediction Center (CPC)], satellite-based data [the Global Precipitation Climatology Project (GPCP) one-degree daily and TRMM Multisatellite Precipitation Analysis (TMPA) datasets] and model-based data [the NCEP-DOE AMIP-II re-analysis (NCEP-2) and 40-year ECMWF Re-Analysis (ERA-40) datasets]. Each dataset has a common set of meteorological forcing data which are used to run the MGB-IPH hydrological model for the period from January 1998 to August 2002.The average precipitation of all the datasets is 2542. mm for the Negro River basin, with a standard deviation of 317. mm. TMPA and NCEP-2 have the lowest (2216. mm/year) and the highest (3065. mm/year) precipitation rates, respectively. The HOP and CPC datasets agree best with observed discharge. GPCP gives the best results among the ungauged datasets, followed by ERA-40. TMPA and NCEP-2 are found to be the least accurate. TMPA can reproduce the water cycles reasonably well, but underestimates the precipitation fields and discharges over the basin, while NCEP-2 is unable to represent the rainfall quantity and cycles, and the water discharge. Results suggest that gauge-based data are still the most representative of the actual precipitation in the northern Amazon basin. However, some satellite and model-based can reproduce fairly well the water cycle at the basin scale and monthly time step. © 2011 Elsevier B.V.