The development of perennial wheat could have a number of advantages for improving the sustainability of Australian dryland farming systems. The profitability that might be expected from perennial wheat of different types was investigated using MIDAS (Model of an Integrated Dryland Agricultural System), a bioeconomic model of a mixed crop/livestock farming system. Although perennial wheat may produce a lower grain yield and quality than annual wheat, it is expected inputs of fertilizer, herbicide and sowing costs will be lower. Perennial wheat used solely for grain production was not selected as part of an optimal farm plan under the standard assumptions. In contrast, dual-purpose perennial wheat that produces grain and additional forage during summer and autumn than annual wheat can increase farm profitability substantially (AU$20/ha over the whole farm) and 20% of farm area was selected on the optimal farm plan under standard assumptions. Forage from perennial wheat replaced stubble over summer and grain supplement at the break of season and increased farm stock numbers. The additional value added by grazing also reduced the relative yield required for perennial wheat to be profitable. This analysis suggests perennial wheat used for the dual purposes of grain and forage production could be developed as a profitable option for mixed crop/livestock producers.