The relative contribution of microfauna (bacteria and protozoa), and metazoa (meiofauna and macrofauna) to profundal benthic production in Lake Brunnsee was examined in a 1-y study. Abundance of micro-, meio-, and macrofauna was determined and converted to biomass. Annual production was calculated using the [³H]-thymidine incorporation method for bacteria and allometric equations for protozoa and metazoa. Bacteria had the highest biomass and production (1.5 g C/m² and 27 g C m⁻² y⁻¹, respectively). Protozoa had the highest P/B ratio, with an average biomass of 0.1 g C/m² and an annual production of 22 g C m⁻² y⁻¹. Meiobenthos and macrobenthos had biomasses of 0.1 and 1.2 g C/m², respectively, and production estimates of 1.6 g m⁻² y⁻¹ and 3.1 to 6.7 g m⁻² y⁻¹, respectively, depending on the method used for calculation. Although protozoan biomass was small in Lake Brunnsee sediments, production estimates suggest that they may represent an important component of the benthic community.