To evaluate the importance and fate of organic matter inputs in forested streams, we determined the litterfall inputs and the benthic coarse particulate organic matter (CPOM) in one headwater stream flowing through a mixed deciduous forest, during one year. Both vertical traps and the stream bottom were sampled monthly. The material collected was sorted into four main categories: leaves, fruits and flowers, twigs and debris. Litter production was 715 g m-2 y-1 and seasonal, with 73% of the annual total during October-December (autumn). Leaves comprised the largest litter component. Benthic organic matter was 1880 g m-2 y-1, and was also seasonal. Highest accumulation was attained in spring, and twigs and branches comprised the major component.