In the next 20 years, global wheat production must increase by 40 per cent to meet the growing demand. A greater reliance on maximizing production efficiency, or grain yield potential (GYP), under various agro-ecological scenarios will be required. CIMMYT aims to contribute to this effort by protecting past achievements in yield potential and adaptation through continuing an aggressive program of incorporating resistance to abiotic and biotic stresses. This strategy capitalizes on newer empirical methods, advances in information technology, morphological and physiological markers, broadening the genetic resource base and the use of emerging biotechnologies. In this paper, data from trials that assess maximum yield potential are presented, revealing that improved GYP in recently developed CIMMYT durum wheat germplasm has resulted from an increased number of grains m-2.