The macrobenthic fauna of lago Escondido (Río Negro, Argentina) has been sampled from May to November, 1987. Samples were collected with an Ekman‐Birge dredge (263 cm2), along four transects with an 1 meter depth interval. Some physical and chemical parameters were also taken. From the 28 identified taxa, chironomid larvae exhibited the highest values both in species richness and abundance. The most abundant chironomids werePolypedilumsp. (3354 ind./m2) andNimbocerasp. (2312 ind./m2) in the 0–1 m interval. The higest density was observed in the littoral zone (0–5 m), whereSchaenoplectus californicusandPotamogeton linguatusgrow; in which the maximum value was 8224 ind./m2between 0 and 1 m. The lowest density (303 ind./m2) was detected in the zone without vegetation (7–8 m). The faunistic composition of lake Escondido showed some differences with similar temperate lakes in the Northern hemisphere and Australia, e.g. it lacks the predaceous chaoborid larvae; and similarities with the New Zealand lakes but with higher species richness of chironomids.