This study investigated whether yield advantages of the wheat cultivar ‘Drysdale’ (selected for high transpiration efficiency) over recurrent parent ‘Hartog’ (low transpiration efficiency) are maintained under future atmospheric CO 2 . Growth, yield and yield components at three developmental stages (stem elongation, anthesis, maturity) were evaluated at two CO 2 concentrations (ambient, a[CO 2 ], ∼390μmolmol −1 and elevated, e[CO 2 ], ∼550μmolmol −1 ). Growth under e[CO 2 ] stimulated yield and above ground biomass on average by ∼18%. ‘Hartog’ compared to ‘Drysdale’ had significantly greater crop growth rate (∼14%), above ground biomass (∼15%), leaf area index (∼25%) and tiller numbers (∼16%) during early development (stem elongation). ‘Hartog’, however, lost this initial growth advantage over ‘Drysdale’ until anthesis when ‘Drysdale’ had more green leaf mass (∼15%) and greater spike (∼8%) and tiller (∼11%) numbers, particularly when grown under e[CO 2 ]. At maturity, this resulted in a yield advantage of ∼19% of ‘Drysdale’ over ‘Hartog’ when grown under e[CO 2 ] but only of ∼2% under a[CO 2 ]. We suggest that wheat cultivars selected for superior transpiration efficiency will remain successful in a high [CO 2 ] world. Evidence from this study even indicates that such cultivars may confer future advantage in some environments where this is not evident under current [CO 2 ].