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Adaptive rangeland management based on continuous grazing by sheep was implemented at Los Pozos station, on the Magellan tussock steppes of southern Patagonia, between 1990 and 2010. The numbers of sheep were adjusted annually following a stocking strategy tracking the herbage mass. Herbage mass was assessed by harvesting short grass species at peak herbage mass and grazing capacity was estimated based on sheep requirements. Historic production records under a traditional continuous grazing management (1930-89) were contrasted with those of the adaptive management period (1990-2010). Stocking rates of 0.59 sheep ha-1 year-1 in the period from 1930 to 1989 dropped to 0.35 sheep ha-1 year-1 in the adaptive management period. Mean herbage mass of short grasses during this latter period was 194±12kg DM ha-1 and the stubble height of the key species, Poa spiciformis, was 24±0.7mm. Lamb marking rates and extraction rates increased from 72 to 87%, and from 28 to 48%, respectively, under adaptive management when compared with historic management, and historic levels of sheep sales were maintained: 4405 v. 4602 animals year-1. Wool production fell from 36102 to 26771kg year-1. Annual sheep production under adaptive management was less variable, as the annual coefficient of variation fell by 41% for lambing rates, by 25.8% for wool production, and by 40% for sheep extraction rates, compared with historic records, even though the inter-annual rainfall coefficient of variation increased by 25% over the same period. It is concluded that, under adaptive management, herbage production, stubble height and sheep production remained stable over 20 years. The adaptive strategy allowed a stabilisation of production and is a potentially valuable management tool in view of the expected increase in variability of rainfall predicted by global climate models for Patagonia and other rangeland areas.