We report the effects of sediments released by road construction on litter degradation in Amazonian forest streams. Four impacted streams and one control were studied between October and December 2007. In each stream 10 nylon bags (1-cm² mesh) were placed with a spacing of 25 cm. Each bag contained 4.034g (±0.023) of Mabea speciosa (Euphorbiacea) dried for three days at 50°C. Two bags were removed from each stream on day 7, 14, 25, 35 and 60. Litter degradation was slow in the absence of suspended inorganic sediment (F=0.62, p=0.44) or of macroinvertebrate fragmenters. By day 60, the bags in the control stream had lost 25% of their weight on average, while loss in the impacted streams was 35-53%, except for one stream with 15% loss where the bags were buried under 5 cm of sediment. We did not find weight loss to be related either to the abundance (F=0.79 p=0.38) or to the richness (F=3.79, p=0.06) of macroinvertebrates. Considering all streams, the fauna was composed of collectors (48%, ±18), scrapers (24%, ±10) and predators (21%, ±8). Fragmenters and filter feeders were scarce in all streams (>3% in total). The percentage of scrapers was directly related to weight loss (F=4.44, p=0.04).