The hydrometrie station on the River Amazon at Obidos gauges the world's largest river basin (4.8 × 106 km2), and the mean flow measured at this station (172 000 m3 s-1) represents 80% of the water flux of the Amazon to the Atlantic Ocean. Since 1995, a regular 10-day programme of surface sampling of suspended sediment has been in operation, with the aim of documenting the temporal variability of the sediment flux of the Amazon. Calibration of the surface samples with the results of detailed sampling of sediment concentrations in the cross section provided by 18 sampling campaigns, has made it possible to generate a continuous record of sediment transport for the River Amazon at Obidos for the period 1995-2003. These data have highlighted the marked seasonality in the sediment flux, unconnected to the variation of discharge, and provide an estimate of the mean annual suspended sediment flux of 810 106 t year-1.