An earlier study of district-level agricultural total factor productivity in the Western Cape province of South Africa Conradie et al. (2009a, b) is extended to include eleven Northern Cape districts that in combination make up the Karoo. Tornqvist Theil total factor productivity (TFP) indices are calculated using accounting data from 10 years of the farm census between 1949/50 and 2001/2. The Northern Cape districts experienced the same general productivity decline as those of the Western Cape’s Central Karoo. Both parts of the broader Karoo region show a similar mean rate of decline. However, the reasons for this are different, with developments in irrigation systems a major factor.